Methods, devices and formulations for targeted endobronchial therapy

ABSTRACT

The present invention provides an improved means of treating tracheobronchitis, bronchiectasis and pneumonia in the nosocomial patient, preferably with aerosolized anti gram-positive and anti-gram negative antibiotics administered in combination or in seriatim in reliably sufficient amounts for therapeutic effect. In one aspect, the invention assures this result when aerosol is delivered into the ventilator circuit. In one embodiment the result is achieved mechanically. In another embodiment, the result is achieved by aerosol formulation. In another aspect, the invention assures the result when aerosol is delivered directly to the airways distal of the ventilator circuit. The treatment means eliminates the dosage variability that ventilator systems engender when aerosols are introduced via the ventilator circuit. The treatment means also concentrates the therapeutic agent specifically at affected sites in the lung such that therapeutic levels of administrated drug are achieved without significant systemic exposure of the patient to the drug. The invention further provides a dose control device to govern this specialized regimen.

FIELD OF THE INVENTION

The invention relates to methods and compositions for treatingtracheobronchitis, bronchiectasis and pneumonia in subjects, includingthe hospital patient. The present invention also relates to preventionof pulmonary infections in patients at increased risk for suchinfections, particularly intubated patients, through the delivery ofantimicrobials to the trachea (and in some embodiments to the deeplung). In particular, the invention provides a means for treating amechanically ventilated patient with an aerosolized antimicrobial agentwithout exposing such patient to significant systemic levels of theagent. Especially, the invention provides a means for administering tomechanically ventilated patients a dose of the therapeutic agent that issubstantially invariant from patient-to-patient when compared to thevariances typical for aorosolized agents administered via the ventilatorcircuit. In another aspect, the invention relates to devices that ensurethe dose-control of which the invention is capable. In a preferredembodiment, the present invention contemplates the use, in combination,of aerosolized antimicrobial agents capable in combination of exerting abactericidal or bacteriostatic effect on gram-positive and gram-negativebacteria in the lung and tracheobronclhial tree to treat or preventpulmonary infections.

BACKGROUND OF THE INVENTION

Mechanical ventilation appears to upset the normal processes that keepthe lungs free of disease. Indeed, ventilator-associated pneumonia (VAP)is reported to be the most common hospital-acquired infection amongpatients requiring mechanical ventilation. There is a strong correlationbetween the duration of intubation and development of infection. In arecent large study, the mean interval between intubation and theidentification of VAP was 3.3 days. Rello J. et al., “Epidemiology andOutcomes of Ventilator-Associated Pneumonia in a Large US Database”Chest 122:2115 (2002). Importantly, once VAP develops, the patientusually requires a more extended period of ventilation. Unfortunately,prolonging the intubation invites new rounds of deep infection withfurther decompensation of respiratory function, in a vicious cycleending frequently in death.

It is well-known to treat such infections with systemically administeredantibiotics, but simultaneous treatment of the whole body with multipleantibiotic agents is fraught with complications that range fromaccelerating the selection of antibiotic-resistant strains to disruptingfluid and electrolyte balance and compromising the antiviral defensemechanisms of mucosal epithelia throughout the body. Systemicallyadministered antibiotics can also have adverse effects on the liver,kidney and skeleton. Such concerns have resulted in a recent call for ade-escalating strategy for antibiotic administration. Hoffken G. andNiederman M. S., “Nosocomial Pneumonia: The Importance of De-escalatingStrategy for Antibiotic Treatment of Pneumonia in the ICU” Chest122:2183 (2002).

Exacerbating the risks cited above is the fact that the objective ofsystemic therapy is to achieve high concentrations of antibiotic not inthe circulation but on the mucosal side of the bronchi, i.e., in thebronchial secretions. Many antibiotics diffuse poorly from thebloodstream across the bronchi [Pennington, J. E., “Penetration ofantibiotics into respiratory secretions,” Rev Infect Dis 3(1):67-73(1981)], which leads the practitioner to administer higher doses ofantibiotic than would be prescribed for a truly systemic infection.Moreover, the purulent sputum that characterizes infected patients tendsto compromise the potency of many antibiotics. See e.g., Levy, J., etal., “Bioactivity of gentamicin in purulent sputum from patients withcystic fibrosis or bronchiectasis: comparison with activity in serum,” JInfect Dis 148(6):1069-76 (1983). This factor further motivates thepractitioner to prescribe large amounts of antibiotic. These dangershave led some experts to propose that treating lung infectionssystemically in nosocomial patients should be abandoned. Unfortunately,known alternatives are not attractive either.

An alternative approach in which antibiotics are applied to the oral,gastric and endobronchial mucosa along with systemic administration hasbeen tried. It is very costly and, in any case, is not associated withany ameliorating effect on mortality. It also invites “outbreaks” ofantibiotic-resistant infections in intensive care units especially whenused indiscriminately.

In another effort to overcome the aforementioned problems associatedwith systemic administration, various attempts have been made toadminister antibiotics directly to the mucosal surface of the lungs ofspontaneously breathing patients in aerosols (liquid droplets or drypowders) delivered via various nebulizers. However, more localizedadministration of antibiotics is controversial. Early studies withaerosolized antimicrobials did not show unambiguously positive results.This may be due, however, to a poor appreciation of the physics ofaerosol administration to the intubated patient. It is now recognizedthat poor system designs and/or improper device usage can result invirtually no aerosol reaching the desired sites in the lungs. “ConsensusStatement: Aerosols and Delivery Devices” Respiratory Care 45:589(2000).

Moreover, even in studies with generally satisfactory results in termsof levels of antibiotic achieved or the reduction in bacterial loadobserved [Eisenberg, J., et al., “A comparison of peak sputum tobramycinconcentration in patients with cystic fibrosis using jet and ultrasonicnebulizer systems. Aerosolized tobramycin study group,” Chest111(4):955-962 (1997); Ramsey, B. W., et al., “Intermittentadministration of inhaled tobramycin in patients with cystic fibrosis.Cystic fibrosis inhaled tobramycin study group,” N Engl J Med340(1):23-30 (1999)], no effort was made to reduce the amount ofantibiotic administered—the nebulizers were charged with quantities ofantibiotic equivalent to doses typically administered systemically.

The administration of antibiotics by nebulization in ventilated patientsis reportedly even less satisfactory (Fuller, H. D., et al., Pressurizedaerosol versus jet aerosol delivery to mechanically ventilated patients.Am. Rev. Respir Dis 1989, 141:440-444; MacIntyre, N., et al., Aerosoldelivery to intubated, mechanically ventilated patients. Crit. Care Med1985, 13:81-84). In ventilated patients, nebulization that bypasses thehumidifier and is actuated only on the inspiration phase of thebreathing cycle has been attempted using a ventilator (Bear II, BearMedical Systems, Riverside, Calif.) of obsolete design (Palmer, et al.,Crit. Care Med 1998, 26:31-39).

The extreme variability in effective dose that known methods of aerosoldelivery engender is not important for conventional drugs such asbronchodilators because of the potency and safety of such agents.Variability is a crucial problem, however, in the case of antibiotics.The risk of pulmonary toxicity discourages the prescription of heroicdoses to overwhelm the variability problem. That leaves the patientexposed to the prospect of inadequate treatment, a particularly riskymatter. In the worst cases, by the time the insufficiency is recognized,the opportunity to correct the situation is past. In many other cases,the insufficient treatment encourages the selection and growth ofantibiotic-resistant organisms in the patient, which totally disarms thepractitioner and exposes entire cohorts of patients to danger.

What is needed in the art to encourage the abandonment of systemicantibiotic therapy to treat lung infections in the nosocomial patient isa means of delivering antibiotics directly into the distal airways ofthe lung. Such means should produce reliably high titers of antibioticsin the bronchial secretions in a short period of time so as to overwhelmall infectious organisms before selection processes can even begin toestablish a population of resistant organisms. On the other hand, theinvention should provide a reliable means of dose control to avoid“spillover” into the systemic circulation, pulmonary toxicity, andinadvertent exposure of medical personnel and other patients to escapedantibiotics.

SUMMARY OF THE INVENTION

These and other objects are furnished by the present invention whichprovides a method for treating or preventing pulmonary infections,including nosocomial infections, in animals, including, especially,humans. The method generally comprises administering to an animalsubject or human patient in need thereof, as an aerosol, atherapeutically effective amount of an antibiotic substance or apharmaceutically acceptable salt thereof. Several antibiotics may bedelivered in combination according to the invention, or in seriatim.Preferably, the amounts delivered to the airways, if deliveredsystemically in such amounts, would not be sufficient to betherapeutically effective and would certainly not be enough to inducetoxicity. At the same time, such amounts will result in sputum levels ofantibiotic of more than about 10-100 times the minimum inhibitoryconcentration (“MIC”).

In one aspect, the therapeutically effective amount reaches the airwaysby means of a nebulizer positioned to direct its aerosol into theventilator circuit. A variety of nebulizers suitable for creatingaerosols as liquid droplets or dry particles are useful in theinvention. In fact, any means of aerosol delivery that tends to minimizetrapping of aerosol particles on the inner walls of the ventilatorcircuit is within the -scope of the invention. In one embodiment, thisobject is achieved by insuring that the aerosolized particles areprevented from undergoing significant hygroscopic enlargement, sinceparticles enrobed in water will tend to condense on the walls. In oneembodiment, the step is introduced of reducing humidity in theventilator circuit by a predetermined amount before nebulization begins.In this embodiment, according to the invention, a humidity thatmaintains mass median aerodynamic diameter (“MMAD”) at less than about 3μm as predetermined in a standard bench-test model is preferred, and anMMAD less than about 1.5 μm is more preferred. In another embodiment,each aerosol particle is delivered enrobed in a substantiallyanhygroscopic envelope.

Of course, embodiments can be used where diameters are greater.Moreover, in some cases, the present invention contemplates adjustmentsto the surface electrical charges on the particles or the walls. Forexample, assuming surface charge on the device is important, the presentinvention contemplates embodiments wherein the connectors are made, orthe Y piece (discussed below) is made, of metal (or at least coated withmetal). Alternatively, the plastic connectors and/or Y piece can betreated with agents (e.g. wetting agents, detergents, soaps) to adjustsurface charge.

In another aspect of the invention, aerosolized antibiotic is delivereddirectly to the airways of the animal subject or human patient, largelyby-passing the ventilator circuit. A particularly convenient means fordelivering aerosolized antibiotic according to the invention isdescribed in U.S. Pat. Nos. 5,642,730, 5,964,223 and 6,079,413, herebyincorporated by reference. Since the treatment strategy in which theinstant invention is useful benefits from placement of a specializedsuction catheter in the patient's airway as described below, oneembodiment of this aspect of the instant invention is a combinationaerosol and suction catheter.

Any such delivery device is within the scope of the invention if it iscapable of delivering a predictable amount of a therapeutic agent withinthe ranges contemplated in the invention. Preferably, this requirementis achieved with a device for containing the prescribed amount oftherapeutic agent, which device is another aspect of the invention. Suchdevice, according to the invention, is sized to accommodate thatspecific quantity of antibiotic which, in a predetermined deliveryperiod, will result in the delivery of a predetermined amount ofantibiotic. Such device is designed to operatively fit an aerosoldelivery device that is within the scope of the invention.

In one embodiment, the present invention contemplates a devicecomprising a fluid driving element attached to a dose metering element,said dose metering element engaged to an aerosolizing catheter. In apreferred embodiment, the dose metering element is detachably engaged tosaid aerosolizing catheter and comprises a reservoir of defined volume,said reservoir being preferably configured as a transparent orsemi-transparent cylinder or tube, with or without visible measurementindicia. In this preferred embodiment, the fluid formulation (e.g.antibiotic formulation) for the patient is placed in the reservoir, thefluid driving element being disposed in relation to the reservoir suchthat, in operation, the fluid driving element urges the fluidformulation ouf ot eh reservoir and into the aerosolization device. In apreferred embodiment, the fluid driving element comprises a plunger orpiston driven by compressed gas, said compressed gas stored in acontainer or canister and released by the operator of the device. Whenthe release of compressed gas is triggered, the plunger or piston pushesthe defined volume of the formulation into the aerosolizing catheter. Ina particularly preferred embodiment, the device is a “stand alone”device configured such that it can engage an opening or port in aventilation system, wherein said aerosolizing catheter is dimensioned tofit inside (or along side) an endotracheal tube (and/or tracheostomytube) of an intubated patient, such that the delivery end (i.e. out ofwhich the aerosol is delivered) of the catheter extends approximately tothe end of the tube (or preferably below the end of the tube, therebydelivering aerosol in a manner that bypasses the tube). In aparticularly preferred embodiment, the end of the aerosolizing cathetercomprises a baffle to slow the speed of the aerosol.

In a preferred embodiment, the drug or drugs in the formulation areantimicrobials (i.e. antifungals, antivirals, and/or antibacterials). Ina particularly preferred embodiment, the present invention contemplatesa formulation comprising an anti-gram positive antibiotic substancetogether with an anti-gram-negative antibiotic substance, orpharmaceutically acceptable salts thereof, in an aerosolizing device. Inone embodiment, the method comprises: a) providing: i) a patient(whether human or animal) exhibiting one or more symptoms of infection(or simply a patient at risk for infections); ii) a formulation(typically a liquid, dry powder or lipid formulation) comprising a firstantibiotic having activity against gram positive bacteria and a secondantibiotic having activity against gram negative bacteria; iii) anaerosol delivery device comprising an upper end and a lower end, saidlower end comprising an aerosol delivery end configured to fitwithin-said patient's trachea (or within the endotracheal ortracheostomy tube); b) inserting said aerosol delivery end of saiddevice within said patient's trachea to create a positioned device; andc) aerosolizing said formulation under conditions such that saidformulation is delivered through said aerosol delivery end of saidpositioned device to said patient, wherein said aerosol first contactssaid patient at said patient's trachea (thereby bypassing theoro-pharynx). It is not intended that the above-mentioned embodiment ofthe present invention be limited by the delivery device. In oneembodiment, said aerosol delivery device comprises an aerosol deliverycatheter. In another embodiment, said aerosol delivery device comprisesa bronchoscope fitted with an aerosolizing nozzle. In yet anotherembodiment, said aerosol delivery device comprises a metered doseinhaler fitted with a nozzle extension.

The embodiment of the method of administering a mixture of antibioticsis particularly appropriate for intubated patients. To that end, thepresent invention contemplates an embodiment of the method, comprising:a) providing: i) a patient (whether human or animal) exhibiting one ormore symptoms of microbial infection (or simply a patient who—because ofthe intubation, or length of time intubated—is at risk for infection),said patient being intubated with a tube selected from endotrachealtubes and tracheostomy tubes, said tube having a lower end and an upperend; ii) a formulation (typically a liquid, dry powder or lipidformulation) comprising a first antibiotic having activity against grampositive bacteria and a second antibiotic having activity against gramnegative bacteria; iii) an aerosol delivery catheter comprising an upperend and a lower end, said lower end comprising an aerosol delivery endconfigured to fit within said tube; b) inserting said aerosol deliveryend of said catheter within said tube to create a positioned catheter;and c) aerosolizing said formulation under conditions such that saidformulation is delivered through said positioned catheter to saidpatient. In a preferred embodiment, said tube is connected to amechanical ventilator. In a particularly preferred embodiment, saidaerosol delivery end of said positioned catheter extends to i) justbefore (e.g. within an inch), ii) at or iii) just below (e.g. within aninch) said lower end of said tube (thereby bypassing potential blockagescaused by the ventilation tubing). However, in one embodiment, saidaerosol delivery end of said positioned catheter is well within theendotracheal tube (positioned in the upper one third or middle one thirdof the endotracheal tube) such that said aerosol first contacts theendotracheal tube and thereafter contacts the patient's trachea.

In one embodiment, particular with respect to “constant-flow”ventilators, the present invention contemplates limiting the deliveryevent strictly to the inspiratory phase of the ventilator cycle and, ifpossible, at a reduced flow-rate. Thus, in one embodiment, saidaerosolizing of step (c) is actuated on (or in fixed realtion to) theinspiration phase of the breathing cycle. In one embodiment, amechanical ventilator controls a breathing cycle for the patient, saidcycle comprising an inspiration phase of the breathing cycle.

In another embodiment, delivery is through the catheter is “continuous”and not limited to the inspiratory phase. In one embodiment, avancomycin/gentamycin formulation is delivered continuously via anaerosol catheter (such as the Trudell catheter).

It is not intended that the present invention be limited to particulardosages. On the other hand, the efficiency of the aerosol systems andmethods described herein permit amounts to be delivered that are too lowto be generally effective if administered systemically, but arenonetheless effective amounts when administered in a suitable andpharmaceutically acceptable formulation directly to the airway.Importantly, while efficiencies can be increased, in preferredembodiments efficiencies are not increased at the expense of controlover the dose. Thus, lower efficiencies are contemplated as preferredwhen delivery is more reproducible.

It is not intended that the present invention be limited toantimicrobials that only kill particular organisms. The presentinvention contemplates drugs and drug combinations that will address awide variety of organisms. In a preferred embodiment, the presentinvention contemplates drugs or drug combinations effective in thetreatment of infections caused by P. aeruginosa, S. aureus, H.influenza, and S. pneumoniae and/or antibiotic-resistant strains ofbacteria such as methicillin-resistant S. aureus, among others.

Of course, antivirals can also be aerosolized and administered in themanner of the antibiotic formulations of the present invention. This isparticularly significant given the outbreak of severe acute respiratorysyndrome (SARS) in Hong Kong. The symptoms of SARS include fever,chills, myalgia and cough. People of older age, people with lymphopenia,and people with liver dysfunction typically are associated with severedisease. It is believed that the infectious agent is a virus belongin tothe family Coronaviridae.

While preferred embodiments of the present invention address infections,the present invention contemplates that the improved aerosol systems andmethods can be applied to any patient, human or animal, in need of anaerosol to the trachea and/or deep lung. For this reason, other drugs(e.g. steroids, proteins, peptides, nucleic acids, bronchodilator,surfactant, lidocaine . . . ) are contemplated as aerosols. Moreoverother types of patients (e.g. cystic fibrosis, lung cancer, COPH, ARDS,SAID, Heaves, respiratory infections, asthma, bronchospasm) arecontemplated.

Moreover, while preferred embodiments of the present invention arepresented in the context of the intubated patient, other patients atrisk for infection are contemplated as treatable with the methods anddevices of the present invention. For example, the elderly (particularlythose in nursing homes), horses, dogs and cats in competitions (show andracing animals), animals that frequently travel (e.g. circus animals),animals in close quarters (e.g. zoos or farms), humans and animals ingeneral are at risk for lung infections. The present inventioncontemplates delivery of aerosols to the trachea and/or deep lung forsuch individuals—both prophylactically (i.e. before symptoms) and underacute conditions (i.e. after symptoms)—wherein said aerosols compriseantimicrobials, and in particular, the antibiotic mixtures describedabove.

In one embodiment, the present invention contemplates administering theappropriate medication to a patient diagnosed with ARDS or chronicobstructive pulmonary disease (COPD). This invention contemplates anembodiment of a method, comprising: a) providing: i) a patient (whetherhuman or animal) exhibiting one or more symptoms of ARDS (or simply apatient who, because of prior diagnosis with chronic or acute conditionsof AIDS, tuberculosis, flu, emphysema, cystic fibrosis, heaves, iseither currently infected or at risk for infection, or who exhibitsincreases in mucus or sputum), ii) a formulation of the appropriatemedication, and iii) an aerosol delivery catheter comprising an upperend and a lower end, said lower end comprising an aerosol delivery end;b) inserting said aerosol delivery end of said catheter into saidpatient's trachea to create a positioned catheter (if the patient has anintubation tube the catheter is configured to fit inside or along sidesaid tube); and c) aerosolizing said formulation under conditions suchthat said formulation is delivered through said positioned catheter tosaid patient.

The present invention is not limited to any precise desired outcome whenusing the above-described compositions, devices and methods. However, itis believed that the compositions, devices and methods of the presentinvention may result in a reduction in mortality rates of intubatedpatients, a decrease in the incidence of resistance (or at least noincrease in resistance) because of the reduced systemic antibioticexposure and elevated exposure at the targeted mucosal surface of thelung caused by local administration. As noted above, it is contemplatedthat the compositions, devices and methods of the present invention areuseful in the treatment of pneumonia (and may be more effective thansystemic treatment—or at the very least, a useful adjunct). It isbelieved that related infections may also be prevented or reduced (e.g.prevention of sepsis, suppression of urinary tract infections, etc.)

Of course, a reduced use of systemic antibiotics because of the efficacyof the compositions, devices and methods of the present invention mayresult in reduced cost, reduced time on IV lines, and/or reduced time oncentral lines). Moreover, such a reduction should reduce antibiotictoxicity (as measured by reduced incidence of diarrhea and C. difficileinfection, better nutrition, etc.)

It is believed that the compositions, devices and methods of the presentinvention will locally result in a reduction of the ET/Trach tubebiofilm. This should, in turn, get rid of secretions, decrease airwayresistance, and/or decrease the work of breathing. The latter shouldease the process of weaning the patient off of the ventilator

The present invention contemplates specific embodiments that can replacecommonly used elements of a ventilator system. In one embodiment, thepresent invention contemplates a modular Y piece attachable to aventilator and to an endotracheal tube, wherein the lower arm of the Ypiece comprises an aerosol generator. While not limited to any precisedesired outcome, it is contemplated that the modular Y piece withintegral generator will reduce the effects of the ventilator on allconventional aerosol systems (jet, ultrasonic and MDI), and at the sametime enhance the positive qualities of a device like the Aerogen™ pro.Again, While not limited to any precise desired outcome, it iscontemplated that the modular Y piece with integral generator will: (1)reduce variability in delivery (reduced effects of humidification, biasflow, continuous vs breath-actuated) so as to achieve the same delivery(no matter what commercial ventilator system is used); (2) allow formaximal effects of breath actuation; and (3) allow for maximal effect toenhanced nebulizer efficiency using nebulizers having no dead volume.

In one embodiment, the present invention contemplates a method,comprising: a) providing: i) a patient, said patient intubated with atube selected from endotracheal tubes and tracheostomy tubes (whether ornot said patient is exhibiting signs of infection), said tube having alower end and an upper end; ii) a formulation comprising a firstantibiotic; iii) a aerosol delivery device comprising an upper end and alower end, said lower end comprising an aerosol delivery end configuredto fit within said patient's trachea; b) inserting said aerosol deliveryend of said device within said patient's trachea to create a positioneddevice; and c) aerosolizing said formulation under conditions such thatsaid formulation is delivered through said aerosol delivery end of saidpositioned device to said patient, wherein said aerosol first contactssaid trachea. In one embodiment, said aerosol delivery device comprisesan aerosol delivery catheter. In another embodiment, said aerosoldelivery device comprises a bronchoscope fitted with an aerosolizingnozzle. In yet another embodiment, said aerosol delivery devicecomprises a metered dose inhaler fitted with a nozzle extension.

While the present invention is not limited to the nature of theformulation, in one embodiment, said formulation further comprises asecond antibiotic, wherein said first antibiotic has activity againstgram positive bacteria and said second antibiotic has activity againstgram negative bacteria. In yet another embodiment, the formulationfurther comprises a bronchodilator (e.g. albuterol).

In one embodiment, the present invention contemplates a method,comprising: a) providing: i) an intubated patient exhibiting one or moresymptoms of microbial infection, ii) a formulation comprising a firstantibiotic having activity against gram positive bacteria and a secondantibiotic having activity against gram negative bacteria; iii) aaerosol delivery catheter comprising an upper end and a lower end, saidlower end comprising an aerosol delivery end configured to fit withinsaid tube; b) inserting said aerosol delivery end of said catheterwithin said tube to create a positioned catheter; and c) aerosolizingsaid formulation under conditions such that said formulation isdelivered through said positioned catheter to said patient. Over time,it is contemplated that such administration will reduce (but need noteliminate completely) one or more of said symptoms. For example, suchadministration may reduce the CPIS score (discussed in more detailbelow) or may reduce one or more factors used to calculate the CPISscore. On the other hand, such administration may reduce the amount ofsecretions (e.g. sputum) in a defined time period.

While the present invention is not limited to any precise configuration,it is contemplated that the above-described method is performed in thecontext where said tube is connected to a mechanical ventilator. Whilethe present invention is not limited to the precising timing ofdelivery, in one embodiment said mechanical ventilator controls abreathing cycle, said cycle comprising an inspiration phase of thebreathing cycle and said aerosolizing of step (c) is actuated on theinspiration phase of the breathing cycle.

The present invention is not limited to any precise positioning of thecatheter, In one embodiment, said aerosol delivery end of saidpositioned catheter extends i) just before (e.g. within 3 cm), ii) at,or iii) just below (e.g. with 3 cm) of said lower end of said tube.However, in one embodiment, said aerosol delivery end of said positionedcatheter is well within the endotracheal tube (positioned in the upperone third or middle one third of the endotracheal tube) such that saidaerosol first contacts the endotracheal tube and thereafter contacts thepatient's trachea.

In yet another embodiment, the present invention contemplates a method,comprising: a) providing: i) a patient exhibiting an elevated whiteblood cell count (and/or an elevated CPIS score); ii) a formulationcomprising a first antibiotic having activity against gram positivebacteria and (optionally) a second antibiotic having activity againstgram negative bacteria; iii) a aerosol delivery device comprising anupper end and a lower end, said lower end comprising an aerosol deliveryend configured to fit within said patient's trachea; b) inserting saidaerosol delivery end of said device within said patient's trachea tocreate a positioned device; and c) aerosolizing said formulation underconditions such that said formulation is delivered through said aerosoldelivery end of said positioned device to said patient to create atreated patient, wherein said aerosol first contacts said trachea. Overtime, it is contemplated that such administration will reduce the whiteblood cell count (in some cases to a number in the normal range).Therefore, in one embodiment, the method further comprises d) measuringthe white blood cell count of said treated patient after step (c).

However, white blood cell count is only one of a number of indicators.By way of example, such administration may reduce the CPIS score [e.g.from 6 (or >6) to 4 or less] or may reduce one or more factors used tocalculate the CPIS score. On the other hand, such administration mayreduce the amount of secretions (e.g. sputum) in a defined time period.

Again, while the present invention is not limited to any preciseconfiguration, it is contemplated that the above-described method isperformed in the context where said tube is connected to a mechanicalventilator. While the present invention is not limited to the precisingtiming of delivery, in one embodiment said mechanical ventilatorcontrols a breathing cycle, said cycle comprising an inspiration phaseof the breathing cycle and said aerosolizing of step (c) is actuated onthe inspiration phase of the breathing cycle.

Again, the present invention is not limited to any precise positioningof the catheter, In one embodiment, said aerosol delivery end of saidpositioned catheter extends i) just before (e.g. within 3 cm), ii) at,or iii) just below (e.g. with 3 cm) of said lower end of said tube.

The present invention also contemplates devices and formulations(independent of how they are used). While the present-invention is notlimited to the nature of the formulation, in one embodiment, saidformulation further comprises a first antibiotic with activity againstgram positive bacteria and a second antibiotic with activity againstgram negative bacteria. In yet another embodiment, the formulationfurther comprises a bronchodilator (e.g. albuterol). In one embodiment,a single antibiotic is used together with a bronchodilator. It has beenfound that this combination is useful due to, the observation (in somecases) of a post-antibiotic bronchospasm when antibiotic is used alone.

In one embodiment, the present invention contemplates a device,comprising a fluid driving element attached to a dose metering element,said dose metering element engaged (directly or indirectly through otherelements) to an aerosolizing catheter, said catheter comprising anaerosol delivery end. In a preferred embodiment, said dose meteringelement is detachably engaged (e.g. screw mounted, snap mounted, slidemounted and held by virtue of the fact that the tubing slides over orslides within other tubing) to said aerosolizing catheter. In oneembodiment, said dose metering element comprises a reservoir of definedvolume. In one embodiment, said reservoir is loaded with a drugformulation (e.g. an antibiotic formulation). In one embodiment, saidreservoir is configured as a transparent or semi-transparent cylinder.In one embodiment, said cylinder comprises visible measurement indicia.In one embodiment, said fluid driving element comprises a plunger drivenby compressed gas, said compressed gas stored in a canister. In oneembodiment, said aerosolizing catheter is of such dimensions such thatit can to fit inside an endotracheal tube. In one embodiment, saiddelivery end of said aerosolizing catheter comprises a baffle.

In one embodiment, the present invention also contemplates a devicecomprising tubing configured approximately as a Y piece, said devicehaving a first end attachable to a ventilator and a second endattachable to an endotracheal tube, wherein said second end comprises anaerosol generator. In one embodiment, said aerosol generator is integralto said second end (e.g. attached at the time of molding the piece). Inone embodiment, said aerosol generator is drug-loaded.

In another embodiment, the present invention contemplates a systemcomprising a ventilator circuit, said circuit comprising i) aninspiratory line and an expiratory line converging at a junction, ii) anebulizer positioned in proximity to said junction and in fluidcommunication with an endotracheal tube (or tracheostomy tube), whereinsaid nebulizer is not positioned in said inspiratory line or saidexpiratory line. The nebulizer is positioned “in proximity” to saidjunction when it is placed between said junction and said endotrachealtube (and optionally, it can be placed so that it is closer to saidjunction than it is to said endotracheal tube).

It is not intended that the present invention be limited to the preciseconfiguration of the junction. In one embodiment, said junctioncomprises a Y piece (or “T” piece, or “V” piece) having a first end, asecond end, and a stem (the “V” piece stem is just the bottom point ofthe “V”). It is preferred in this embodiment that said inspiratory lineis attached to said first end of said Y piece, and wherein and saidexpiratory line is attached to said second end of said Y piece. In oneembodiment, said nebulizer is positioned in said stem of said Y piece.In one embodiment, said nebulizer is simply attached to said stem ofsaid Y piece. In a preferred embodiment, a nebulizer adapter is insertedbetween the Y piece and the endotracheal tube such that said nebulizercan be positioned (i.e. the nebulizer fits into the adapter in amale-female manner, as a snap fit, etc). In yet another embodiment, saidnebulizer is integral to said stem of said Y piece.

The present invention is not limited to the precise configuration ornature of the circuit. In one embodiment, said circuit is a closedcircuit. In another embodiment, said circuit is an open circuit.

The present invention also contemplates an embodiment of a devicecomprising tubing configured approximately as a Y piece (or “T” piece,or “V” piece), said device comprising i) a first end attachable to aninspiratory line of a ventilator circuit, ii) a second end attachable toan expiratory line of a ventilator circuit, and iii) a stem comprisingan nebulizer. In one embodiment, said nebulizer is positioned in saidstem of said Y piece. In one embodiment, said nebulizer is simplydirectly or indirectly (e.g. via another tube or suitable element)attached to said stem of said Y piece. In a preferred embodiment, anebulizer adapter is inserted between the Y piece and the endotrachealtube such that said nebulizer can be positioned (i.e. the nebulizer fitsinto the adapter in a male-female manner, as a snap fit, etc). In yetanother embodiment, said nebulizer is integral to said stem of said Ypiece. The nebulizer can either be empty (loaded later) or drug-loaded(provided to the end user in a loaded form).

While not limited to how the above devices are used, in one embodimentthe present invention contemplates a method comprising a) providing asubject attached to a ventilator circuit via a tube selected from anendotracheal tube and a tracheostomy tube, said ventilator circuitcomprising i) an inspiratory line and an expiratory line converging at ajunction, ii) a nebulizer positioned in proximity to said junction andin fluid communication with said tube, wherein said nebulizer is notpositioned in said inspiratory line or said expiratory line; b)administering aerosolized antibiotic to said subject via said nebulizer.The subject might be a human or animal. In one embodiment, said subjectis a patient exhibiting one or more symptoms of infection. In oneembodiment, said nebulizer, prior to step (b) contains an antibioticformulation. In one embodiment, said antibiotic formulation comprises afirst antibiotic having activity against gram positive bacteria and asecond antibiotic having activity against gram negative bacteria.

In another embodiment, the present invention contemplates a method,comprising a) providing a patient exhibiting one or more symptoms ofmicrobial infection, said patient intubated with a tube selected fromendotracheal tubes and tracheostomy tubes, said tube connected to aventilator circuit comprising i) an inspiratory line and an expiratoryline converging at a junction, ii) a nebulizer positioned in proximityto said junction and in fluid communication with said tube, wherein saidnebulizer is not positioned in said inspiratory line or said expiratoryline, and wherein said nebulizer contains a formulation comprising twoor more antibiotics; b) administering said formulation as an aerosol tosaid patient via said nebulizer. While not limited to the preciseformulation, in one embodiment said formulation comprises a firstantibiotic having activity against gram positive bacteria and a secondantibiotic having activity against gram negative bacteria.

Again, the present invention is not limited to particular ventconfigurations. In one embodiment, said inspiratory and said expiratorylines are connected to a mechanical ventilator. In one embodiment, saidmechanical ventilator controls a breathing cycle, said cycle comprisingan inspiration phase. In one embodiment, said administering of saidaerosol of step (b) is actuated on the inspiration phase of thebreathing cycle.

Again, the present invention is not limited to particular vent featuresor modes of operation. In one embodiment, said mechanical ventilatorcomprises a humidifying element. In one embodiment, said administeringof said aerosol of step (b) is actuated when said humidifying element isnot active.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram of a conventional endotracheal intubation. FIG. 1Bis a magnified view of the circled area of FIG. 1A

FIG. 2A is a diagram of a patient with a tracheostomy tube and an inlinesputum trap (i.e. as part of the ventilation system). FIG. 2B shows theengagement of an aerosol catheter with a port in the ventilation system.FIG. 2C shows the engagement of an EBC system with a port in theventilation system.

FIG. 3 is a bar graph showing the increase in sputum measured in thesputum trap of FIG. 2 as a function of weeks of intubation.

FIG. 4 is a bar graph showing the relationship of high sputum levels topneumonia (e.g. VAP).

FIG. 5 is a photograph of an exemplary aerosol catheter.

FIG. 6 is a diagram of an aerosol catheter and a suction catheter inoperative combination.

FIG. 7 is a bar graph with data which demonstrates the efficacy ofaerosol antibiotic delivered according to the invention as a function ofsputum volume, which is a determinant of disease.

FIG. 8 is a diagram of a preferred device of the present inventioncomprising a dose metering element, a fluid driving element, and anaerosolizing catheter. The particular embodiment shown depicts a firstportion of the device (comprising the dose metering element and fluiddriving element) as modular and configured to engage the second portionof the device (e.g. in a screw/thread engagement) comprising theaerosolizing catheter, the catheter comprising an external baffle.

FIG. 9A is one embodiment of a bench model for testing aerosol deliveryas a function of ventilator conditions (e.g. humidity, breathing cycle,etc.).

FIG. 9B is another embodiment of a bench model for testing aerosoldelivery, wherein the aerosol source is not linked to the inspiratoryline of the vent.

FIG. 10 is a bar graph with mortality data associated with sputum levelsexceeding 2 cc in a four hour period.

FIG. 11 is a bar graph showing the association of CPIS Score with sputumlevels and post-treatment at the end of the study (EOS).

FIG. 12 is a schematic of one embodiment of a Y piece for use with aventilator, showing numerous alternative placements of an aerosolgenerator in the lower part (e.g. distal arm) of the Y piece.

FIG. 13 is a bar graph showing a reduction in white blood cell countfollowing the administration of aerosolized antibiotic.

FIG. 14 is a flow diagram illustrating exemplary logic for measuringsputum volumne in a ventilated patient in accordance with one embodimentof the present invention

FIG. 15A shows one embodiment of a ventilator circuit comprising i) aninspiratory line and an expiratory line converging at a junction(typically a “T” or “Y” junction), ii) a nebulizer positioned inproximity to said junction (e.g. attached to the stem or integral to thestem) and in fluid communication with an endotracheal tube, wherein saidnebulizer is not positioned in said inspiratory line or said expiratoryline. FIG. 15B shows a ventilator circuit comprising i) an inspiratoryline and an expiratory line converging at a junction (typically a “T” or“Y” junction), ii) a nebulizer positioned in proximity to said junction(e.g. attached to the stem or integral to the stem) and in fluidcommunication with an endotracheal tube, and an inhaled mass filterremoveably positioned (it can be introduced into the line to find outwhat the patient might be taking in—but must be removed before thepatient can actually tak in any aerosol) between the nebulizer and theendotracheal tube, wherein said nebulizer is not positioned in saidinspiratory line or said expiratory line. The inhaled mass filter allowsone to do accurate measurements of what delivery amounts are actuallyreaching the patient.

FIG. 16 shows a bench model wherein the proximal airways (and depositiontherein) are modeled. In FIG. 16A, the aerosol generator is a nebulizer.In FIG. 16B, the aerosol generator is an aerosol catheter.

FIG. 17 shows various embodiments of a device for attaching a nebulizerto a ventilator circuit. FIG. 17A shows a one piece adapter configuredon a first end for attachment to a Y-piece, configured on a second endfor attachment to an endotracheal tube (or tracheostomy tube), andconfigured on a third end (or “stem”) for attachment to a nebulizer.FIG. 17B shows a one piece adapter configured on a first end forattachment to a Y-piece, configured on a second end for attachment to anendotracheal tube (or tracheostomy tube), and configured on a third end(or “stem”) for attachment to a nebulizer, wherein said second endcomprises a flexible section. FIG. 17C shows a one piece adapter with anintegral nebulizer, said adapter configured on a first end forattachment to a Y-piece, and configured on a second end for attachmentto an endotracheal tube (or tracheostomy tube), wherein said second endcomprises a flexible section.

DEFINITIONS

An “aerosol” is herein defined as a suspension of liquid or solidparticles of a substance (or substances) in a gas. The term “charge” isused to describe the amount of drug placed into the delivery system.“Inhaled mass” refers to the actual amount inhaled by the patient.“Deposition” refers to the dose actually deposited in the patient. Withrespect to delivering aerosols according to the various embodiments ofthe present invention, it is preferred that the “deposition” ofantibiotics is always lower than the systemic dose currently used. Onthe other hand, the “charge” may be high depending on device efficiency.Importantly, even with low efficiency delivery, good control overdelivery (reproducible over a small range) is preferred as the means ofcontrolling dose.

The present invention contemplates the use of both atomizers andnebulizers of various types. An “atomizer is an aerosol generatorwithout a baffle, whereas a “nebulizer” uses a baffle to produce smallerparticles. However, the term “nebulizer” in the claims is meant toencompass atomizers.

In one embodiment, the present invention contemplates using thecommercially available Aerogen™ aerosol generator which comprises avibrational element and dome-shaped aperture plate with tapered holes.When the plate vibrates several thousand times per second, amicro-pumping action causes liquid to be drawn through the taperedholes, creating a low-velocity aerosol with a precisely defined range ofdroplet sizes. The Aerogen™ aerosol generator does not requirepropellant.

“Baffling” is the interruption of forward motion by an object, i.e. by a“baffle.” Baffling can be achieved by having the aerosol hit the sidesof the container or tubing. More typically, a structure (such as a ballor other barrier) is put in the path of the aerosol (See e.g. U.S. Pat.No. 5,642,730, hereby incorporated by reference, and in particular FIG.6, element 6). The present invention contemplates the use of a baffle inorder to slow the speed of the aerosol as it exits the delivery device.

A “dose metering element” is an element that controls the amount of drugadministered. The element can, but need not, measure the amount of drugas it is administered. In a preferred embodiment, the element ischaracterized simply as a container of defined volume (e.g. areservoir). In a preferred embodiment, the defined volume is filled bythe manufacturer or hospital professional (e.g. nurse, pharmacist,doctor, etc.) and the entire volume is administered. In anotherembodiment, the reservoir is configured as a transparent orsemi-transparent cylinder with visible measurement indicia (e.g.markings, numbers, etc.) and the filling is done to a desired point(e.g. less than the entire capacity) using the indicia as a guide.

A “fluid driving element” is an element that moves fluid in a directionalong the device. In simple embodiments, the fluid driving elementcomprises a plunger driven by compressed gas, said compressed gas storedin a canister. In other embodiments, it comprises a pump. In still otherembodiments, it comprises a hand actuated plunger (in the manner of asyringe).

One element is in “fluid communication” or “fluidic communication” withanother element when it is attached through a channel, tube or otherconduit that permits the passage of gas, vapor and the like. Indeed, thetubing associated with commercially available ventilators creates a“circuit” for gas flow by maintaining fluidic communication between theelements of the circuit. Ports in the circuit allow for the circuit tobe temporarily open so that devices and drugs can be introduced.“Tubing” can be made of a variety of materials, including put notlimited to various plastics, metals and composites. Tubing can be rigidor flexible. Tubing can be “attached” in a detachable mode or a fixedmode. Tubing is typically attached by sliding into or over (both ofwhich are examples of “slidably engaging”) other tubing or connectors.

A “patient” is a human or animal and need not be hospitalized. Forexample, out-patients, persons in nursing homes are “patients.”

A “patient exhibiting one or more symptoms of microbial infection” mayhave fever or other traditional symptoms, or may exhibit increasesecretions, organisms in the BALF, or other symptoms. A “patient at riskfor infections” includes, but is not limited to, trauma patients,intensive care patients, intubated patients, elderly patients, low birthweight patients and immunocompromised patients.

A “positioned” device is positioned in vivo, i.e. in the context of thepatient. For example, in certain embodiments, it is desired that anaerosol catheter is positioned such that the aerosol first contacts thetrachea. In another embodiment, the aerosol first contacts theendotracheal tube. In another embodiment, the aerosol is simply broughtin contact with the “biofilm” associated with the infection, whether ornot the biofilm extends beyond the trachea.

“Jet nebulizers” draw up liquid by capillary action such that the liquidreaches a jet stream, is drawn into the jet stream, and is shatteredinto small particles.

“Ultrasonic nebulizers” use electric current to produce sound waves thatbreak up liquid into an aerosol. An ultrasonic nebulizer includes aceramic transducer (including piezo electronic technology) that changeselectrical energy into pressure energy. The transducer vibrates at avery high frequency of up to about 1.5 mHz. The vibrational energy istransmitted through Water and focused on a flexible diaphragm thatvibrates. The diaphragm is in contact with the solution to beaerosolized and shakes the solution into particles. At high frequenciesa fine mist is generated. Ultrasonic nebulizers may produce a moreconsistent particle size than do jet nebulizers and may produce verylarge volumes of respirable particles with much greater deposition intothe lungs.

The present invention contemplates in some embodiments utilizingnebulizers and aerosol drug delivery devices based upon piezo electronictechnology (e.g. Pari GmBh (Starnberg, Germany) e-Flow™ electronicnebulizers based on piezo ceramic electronic transducers), includingportable nebulizers and aerosol devices (e.g. Omron Healthcare, IncPortable Ultrasonic Nebulizer, NE-U03V MicroAir) and inhaled drugdelivery technology (e.g. Mystic™ drug inhalation technologyBattellePharma).

“Acute Respiratory distress syndrome” (ARDS) is a sudden, lifethreatening lung failure from inflamed alveoli that fill with liquid. Itis often treated by mechanical ventilation with antibiotics.

Airflow Obstruction (see Heaves (COPD), and SAID).

Bronchodilator An inhaled short-acting aerosol medication typically usedto provide immediate relief by rapidly opening up the airways.

SAID (Small Airway Inflammatory Disease) A disease of the lower airwayscausing cough and exercise intolerance in horses. This is less severethan Heaves.

Heaves (Chronic Obstructive Pulmonary Disease or Chronic ObstructiveLung Disease) is characterized by forced expiratory effort due to thenarrowing of the small airways of the lungs. This condition is alsoknown as chronic obstructive pulmonary disease (COPD).

pMDI (pressurized Metered Dose Inhaler) (also referred to as MDI orMetered Dose Inhaler) This device creates an aerosol upon depressing thecanister. Each time the canister is depressed a single dose ofmedication is dispensed.

Wet Nebulizer (also known as jet nebulizer) A wet nebulizer works bydirecting a high flow of gas against a liquid drug in order to produce amist of tiny droplets or particles.

Further embodiments include drug formulations and combinations oftopical anethetics and disease or condition specific antibiotics (e.g.aerosolized lidocaine and Corus 1020 antibiotic (Corus Pharma Inc.)).

An example of a “dry powder” formulation is formoterol fumerateinhalation powder for asthma and prevention of bronchospasm (Novartis).

DESCRIPTION OF THE INVENTION

Defining The Patient's Condition. While the association of infectionwith mechanical ventilation is clear, the precise nature of the disease(that either causes or is the result of the infection) is not.“Pneumonia” is not a well-defined condition. The so-called “goldstandard” for diagnosing pneumonia is histological examination(typically done post mortem). However, recognition of histologicpneumonia varies among pathologists. Using a study group consisting of39 patients who died after a mean of 14 days of mechanical ventilation,a panel of pathologists did not agree on the diagnosis. Indeed, when thesame slides were examined 6 months later by the same panel, some of thepatients were re-classified. Corley D. E. et al, “Reproducibility of theHistologic Diagnosis of Pneumonia Among a Panel of Four Pathologists”Chest 112:458 (1997). On the other hand, using the same study group, itwas shown that a bronchoaveolar lavage fluid (BALF) with a cellpopulation comprising <50% neutrophils had a 100% negative predictivevalue for histologic pneumonia. In some embodiments, the presentinvention utilizes this BALF measurement as a means of excludingpneumonia/infection in the ventilated patient. In some embodiments, VAPis confirmed by the presence of at least two of the followingcriteria: >or =2% of cells in BALF contain intracellular bacteria foundon direct examination of BALF; protected-specimen brush sample culturewith >or =10³ cfu/ml; or BALF culture with >or =10⁴ cfu/ml. See CombesA. et al., “Incidence and outcome of polymicrobial ventilator-associatedpneumonia” Chest 121-1618 (2002).

While the general literature describes infections in the context of theintubated patient under the general label “VAP” (forventilator-associated pneumonia), the present inventors recognize thatsuch patients at least initially develop a more limited or localizeddisease best described as “tracheobronchitis.” While not intending tolimit the invention in any manner to a particular disease mechanism, itis believed that tracheobronchitis develops at or around theendotracheal tube (particularly at or near the place where the tube is“anchored” with a cuff, e.g. balloon cuff, or at or near the end of thetube) due to invasion into the proximal airway by the mixed flora of theoro-pharynx. In other words, the tube brings the flora of theoro-pharynx down into the trachea, where it grows at the initial site ofinfection. Other hydrophilic organisms such as Pseudomonas may bypassthe oropharynx and colonize the trachea directly using the endotrachealtube or tracheostomy tube as a conduit.

While it is not intended that the present invention be limited to atheory of how disease progresses in the intubated patient, it isbelieved that one can delay or even prevent pneumonia by treating (orpreventing) tracheobronchitis according to the methods and devices ofthe present invention. The present invention contemplates that diagnosisof tracheobronchitis can be readily done by measurement of sputumlevels.

By way of illustration, FIG. 1A is a diagram of a conventionalendotracheal intubation. FIG. 1B is a magnified view of the circledportion of FIG. 1A showing the balloon cuff that anchors theendotracheal tube and schematically shows the local area of infectioncharacteristic of tracheobronchitis. FIG. 2 is a diagram of a patientwith a tracheostomy tube system with an inline sputum trap. FIG. 3 is abar graph showing the increase in sputum measured in the sputum trap ofFIG. 2 as a function of weeks of intubation.

The data of FIG. 3 justifies two alternative approaches to therapy, bothof which are contemplated by the present invention. In one embodiment,the present invention contemplates prophylactic aerosols of antibioticmixtures to the trachea and/or deep lung after approximately seven (7)days of intubation (or after no fewer than 3 days of intubation and noless than approximately 7 days of intubation)—regardless of whethersymptoms of infection are detectable. In another embodiment, a diagnosisof tracheobronchitis is made where the volume of secretions (e.g. sputumlevels) exceed approximately 2 cc in any 4 hour measurement period(regardless of the number of days of intubation).

FIG. 4 is a bar graph showing the relationship of high sputum levels topneumonia (e.g. VAP). While the invention is not limited to any theoryof disease progression, the very high sputum levels (greater thanapproximately 6 cc in any 4 hour measurement period) indicates that thetracheobronchitis has matured into pneumonia, whereas the “no pneumonia”population is believed to have the more localized tracheobronchitis.

Treating Without Testing. In one embodiment, the intubated patients areviewed as “at risk” and the administration of aerosolized antibiotics isprophylactic. In this embodiment, no testing for infection is done.Rather, justification for treatment is provided by the many studies thatindicate that the incidence of infection increases with the timeintubated. In one embodiment, treatment is done after a certain numberof days on a ventilator (e.g. on day three, more preferrably greaterthan three days, still more preferrably, greater than five days, andmore commonly, greater than seven days).

Patient Testing. It is not intended that the present invention belimited to timing or nature of testing. For example, in one embodiment,the present invention contemplates monitoring an intubated patient (e.g.for sputum levels, for bacteria in BALF, etc.) prior to the onset ofsymptoms of infection. In another embodiment, the present inventioncontemplates testing for organisms after symptoms are apparent (e.g.fever, congestion, etc.). The standard symptoms making up the “clinicalpulmonary infection score” can be used in conjunction with the presentinvention:

-   -   (1) body temperature    -   (2) white blood cell count    -   (3) nature of tracheal secretions    -   (4) oxygenation and ARDS    -   (5) chest X-ray findings    -   (6) results of Gram stain and culture of tracheal secretions

In a preferred embodiment, intubated patients are tested (e.g. forsputum levels, for bacteria in BALF, and/or white blood cell count,etc.) as a function of the number of intubation days. For example,testing is done just prior and/or just after intubation to obtain abaseline for later comparison. Thereafter, similar testing is done oneach intubation day thereafter to obtain relative numbers. In thisembodiment, diagnosis of infection is made by showing an increase (e.g.an increase in sputum levels, an increase in bacteria in BALF, and/orincrease white blood cell count, etc.) over time—not just by the use ofabsolute cut-off levels. Of course, cut-off levels can also be used. Forexample, the typical cut-off for the white blood cell count is10,000—below which is normal. In one embodiment, intubated patients witha white blood cell count of 10,000 or more (i.e. an “elevated” WBCcount) are selected for aerosolized drug administration in the mannerdescribed herein.

The present invention also contemplates testing post-treatment (see FIG.7). That is to say, after aerosolized drug is administered, levels (e.g.sputum levels, bacteria levels in BALF, and/or white blood cell count,etc.) are measured to reveal whether the medication is having thedesired impact. For example, in patients with elevated white blood cellcounts, a decrease over time (such as a week, but more preferably,within 72 hours, and still more preferably, within 48 hours or less) inwhite blood cell counts of 10% (more preferably 20% or more) is anindication that the aerosolized drug treatment is having the desiredoutcome. Such a decrease is shown in FIG. 13, wherein a number (“n”) ofantibiotic (either gentamicin, amikacin, or vancomicin) treated (“AA”)and saline control (“Placebo”) patients were tested for their whiteblood count at the beginning or time of randomization (“R”) and at theend of the study (“EOS”).

In one embodiment, the present invention contemplates methods ofselecting patients for treatment (whether in a normal hospital settingor clinical trial) based on sputum levels. As shown in FIG. 10,separating out patients with greater than 2 cc sputum levels in adefined period (e.g. 4 hours) could have a significant impact onmortality. Those patients having greater than 2 cc of sputum showedhigher mortality. Therefore, selecting this group for aerosol treatmentis warranted.

FIG. 11 shows how the CPIS score together with sputum levels might beused to select patients for treatment. At the time of intubation,patients exhibited a CPIS score of approximately 4. At the point where 2cc of sputum was being secreted, the CPIS score was 6 or greater. At thetime of treatment in the study (i.e. the point where the patients wererandomized to receive drug or placebo), the CPIS score was even higher.However, at the end of treatment, the drug treated population showed adramatically reduced CPIS number.

The data of FIGS. 10 and 11 suggest a treatment modality (whether in anormal hospital setting or for clinical trials to evaluate devices anddrugs) wherein intubated patients with a sputum level of 2 cc or greaterare scored using the CPIS system. Those having less than a CPIS score of6 are not treated systemically with antibiotics. Rather, they aretreated with aerosolized drug (e.g. antibiotic cocktail, etc.). Ofcourse, for a clinical trial, one group is randomized for drug and theother placebo. In any event, all patients are given a daily CPIS score.The CPIS score for the treated group should decline (along with sputumlevels). The end points contemplated include, but are not limited to,days on ventilation, development of VA-P (as determined using theCDC-NNIS criteria), CPIS score, sputum levels, BALF cultures, andmortality—or combinations thereof (e.g. a CPIS score of 4 or less andless than 2 cc sputum secreted in 4 hours).

Those having a CPIS score of 6 or greater are first tested for directevidence of infection (e.g. BALF with organisms as measured, for exampleby gram staining). Those patients who are negative (e.g. no detection bygram staining) are not treated systemically with antibiotics. Rather,they are treated with aerosolized drug (e.g. antibiotic cocktail, etc.).Of course, for a clinical trial, one group is randomized for drug andthe other placebo. In any event, all patients are given a daily CPISscore. The CPIS score for the treated group should decline (along withsputum levels). The end points contemplated include, but are not limitedto, days on ventilation, development of VAP (as determined using theCDC-NNIS criteria), CPIS score, sputum levels, and mortality—orcombinations thereof (e.g. a CPIS score of 4 or less and less than 2 ccsputum secreted in 4 hours). Any rise in the CPIS score (and/or othermarker of progressed disease, for example, patients with CFUs of 10,000or more) results in systemic antibiotic treatment.

Those having a CPIS score of 6 or greater who are positive for organisms(e.g. positive by gram staining) are treated systemically withantibiotics. Thereafter (or simultaneously), they are treated withaerosolized drug (e.g. antibiotic cocktail, etc.). Of course, for aclinical trial, one group is randomized for drug and the other placebo.In any event, all patients are given a daily CPIS score. The CPIS scorefor the treated group should decline (along with sputum levels). The endpoints contemplated include, but are not limited to, days onventilation, development of VAP (as determined using the CDC-NNIScriteria), CPIS score, sputum levels, and mortality—or combinationsthereof (e.g. a CPIS score of 4 or less and less than 2 cc sputumsecreted in 4 hours). Any rise in the CPIS score (and/or other marker ofprogressed disease, for example, patients with CFUs of 10,000 or more)results in continued systemic antibiotic treatment. Any decline in theCPIS score (or even just a stable CPIS score with CFUs of less than10,000) results in discontinued systemic antibiotic treatment.

Formulation. The infections of the trachea and lung can be of differenttypes. Some infections are viral; some are fungal (including yeast).More commonly, the infections are bacterial in nature. However, manycases of infection are not single organism infections; polymicrobialinfections are documented. Combes A. et al., “Incidence and outcome ofpolymicrobial ventilator-associated pneumonia” Chest 121-1618 (2002).For this reason, in one embodiment, the present invention contemplatesan antimicrobial mixture or “cocktail.”

In one embodiment, the mixture comprises two or more antimicrobials(e.g. antibiotics) formulated for aerosolization. In a preferredembodiment, the antibiotic combination is selected for the ability tocombat a wide spectrum of gram-positive and gram-negative organisms. Inthis embodiment, testing may be done prior to treatment to confirm acombination of gram-negative and gram-positive bacterial growth in theairways. On the other hand, it is also contemplated that treatment withthe preferred mixture can be done without testing or confirmation of theexistence of both gram-negative and gram positive organisms. In thelatter case, the exigencies of the ICU may make treatment with themixture prudent as a precaution. Such an approach is justified in thatthe aerosolized mixture is directed locally to the infection withminimal (if any) systemic exposure. Treating with the preferred mixturemay ensure against the possibility that the progression of infectioninto the distal airways is actually facilitated when one antibioticregimen follows another. On the other hand, when the type of infectionis known (or suspected due to indicators), treatment with a singleantibiotic appropriate for the infection is contemplated.

In one embodiment, antifungals and antibiotics are used in a mixture. Inyet another embodiment of the present invention, antivirals, antifungalsand antibiotics are used in a mixture. In one embodiment, these mixturesare in particles (e.g. encapsulated particles, microparticles, etc.).

The present invention contemplates compatible antibiotic combinationsthat can be administered simultaneously in a common vehicle (oralternatively in separate vehicles that can be administered together orin series, such as within minutes to within 8 hours of each other) andcan be expected to have similar (although not identical) therapeutictime-courses. The present invention contemplates providing suchpreparations in a formulation that is well-adapted for use in suitableaerosolization devices, since aerosol administration is an efficientmeans for administering the combination treatment directly to thesurfaces of the affected airways while minimizing the exposure of otherparts of the body to antimicrobial levels of antibiotic agents. Suitableaerosol delivery devices are those that deliver predictable amounts oftherapeutic agents directly to the affected areas without picking uporopharyngeal bacteria and transporting them to the deep lung on the onehand, and without disturbing the normal oropharyngeal flora byantibiotic attack on the other. Suitable aerosol delivery devices arealso those selected on the basis of the fact that, in operation, they donot develop blockages due to thicker (and/or more adhesive)formulations.

In another aspect, the present invention provides a pharmaceuticalcomposition comprising, in combination, an anti-gram-positiveantimicrobial agent and an anti-gram-negative antimicrobial agent and apharmaceutically acceptable carrier, excipient and/or diluent selectedfor compatibility with the antimicrobial agents and capable of beingaerosolized. It is not intended that the present invention be limited toparticular carriers, excipients and/or diluents. A variety of suchagents are contemplated. In some embodiments, formulations will includesuch normally employed additives such as binders, fillers, carriers,preservatives, stabilizing agents, emulsifiers, buffers and excipientsas, for example, pharmaceutical grades of mannitol, lactose, starch,magnesium stearate, sodium saccharin, cellulose, magnesium carbonate,and the like. These compositions take the form of solutions or drypowders, and typically contain 1%-95% of active ingredient, preferably2%-70%.

While the present disclosure places an emphasis on human treatment, thetherapeutic preparations can be administered to mammals for veterinaryuse, such as with domestic animals, and clinical use in humans in amanner similar to other therapeutic agents. In general, the dosagerequired for therapeutic efficacy will vary according to the type of useand mode of administration, as well as the particularized requirementsof individual hosts.

DETAILED DESCRIPTION OF THE INVENTION

The certain preferred embodiments of the present invention, delivery ofthe aerosol is done in a manner that avoids the variability of humidityand other factors (e.g. flow rates, differences in tubing, differencesin the ventilator, etc.). In one embodiment, this involves the use of anaerosol generator (whether via a nebulizer, an aerosolizing catheter, orthe like) positioned between the patient and the junction (typically a Ypiece) of the inspiratory and expiratory lines. In some embodiments, theaerosol generator is attached to (or an integral part of) the Y piece.The advantages of certain embodiments are discussed below inrelationship to conventional arrangements.

Humidity-sensitive nebulization. For any given ventilator andnebulization device, a suitable predetermination of the humidity to beselected may be made using a bench model (FIG. 9A). In use, a testventilator is connected to a test lung (e.g., M.I.I. VentAiTTL, MichiganInstruments, Inc., Grand Rapids, Mich.) via a number 8 endotrachealtube. Aerosols are sampled just distal to the endotracheal tube with aninhaled mass filter, (Pari, GmbH, Starnberg, Germany) and a leak filterin the expiratory line. Aerosols are generated by nebulization with thedevice located in the inspiratory line 12 inches from the Y piece. Anyof a number of test substances may be employed. Among the variables thatcan be evaluated for each ventilator are:

-   -   Relative humidity in the ventilator circuit    -   Frequency and timing of nebulization events during the        ventilator cycle (the “nebulization algorithm”)    -   Bias flow rate    -   Elements of nebulizer performance (drive pressure, initial        particle size, powder aerosol, liquid aerosol, anti-hygroscopic        enrobement aerosol formulations, etc.)    -   Parameters measured for each of the variables are:    -   Inhaled Mass (%), the amount of drug on the filter as a percent        of the nebulizer charge    -   Mass Balance (% Recovery), the sum of both filters plus remnant        activity in the nebulizer    -   Mass Media Aerodynamic Diameter (MMAD)

The artisan will find in the bench test of any given ventilator ahumidity setting that maintains the MMAD of the aerosol within thepreferred range of the invention as a function of bias flow rate, thenebulization algorithm and the specific performance of the nebulizer. Inthe case of the arrangement shown in FIG. 9A, good delivery ofaerosolized drug can be achieved by actuating the nebulizer when thehumidity feature of the vent is not active. Thus, in one embodiment, thepresent invention contemplates the delivery of a formulation comprisingtwo or more antibiotics using an arrangement wherein the nebulizer ispositioned in the inspiratory line. Preferrably, this embodiment isemployed under modified humidity conditions (i.e. conditions such thathumidity does not significantly impair delivery).

Another embodiment of a bench model is shown in FIG. 9B. Again, aerosolsare sampled just distal to the endotracheal tube with an inhaled massfilter, (Pari, GmbH, Starnberg, Germany); optionally, Expiratory andInspiratory line filters can be employed. Aerosols are generated bynebulization with the device located outside of the inspiratory line(i.e. not in the inspiratory line) and within the Y piece (preferablytoward the end of the Y piece that connects with the ET tube). Again,any of a number of test substances may be employed. Of course, thepresent invention contemplates, in one embodiment, using the arrangementof FIG. 9B in the context of a patient, wherein a formulation comprisingat least one antibiotic is aerolized and administered. With theembodiment represented in FIG. 9B, a more consistent (albeit lowerefficiency) dosing is observed. This illustrates one advantage ofaerosol entry in the Y piece.

Non-hygroscopic enrobement of aerosolized therapeutic agent. A largenumber of microencapsulation technologies are known in the art, many ofwhich will render the aerosolized particles of the invention resistantto rainout onto the walls of the humid ventilator circuit. Although anyaerosol particle that is anhygroscopic is with the scope of theinvention, a recently disclosed and particularly apt technology for theenrobement purpose is described and claimed in U.S. Pat. No. 6,403,057to Schneider and Bussat, and is incorporated herein by reference.According to that invention, a microcapsule with a mean size from afraction of a μm to 1,000 μm may be obtained when one or morebiodegradable, water insoluble lipids are used to encapsulate a corewhich comprises, initially, air or a gas. The process results inmicrocapsules of significant mechanical strength in the form of anon-coalescent, dry and instantly dispersable powder. Composed as theyare of biodegradable lipids, the microcapsules last in the body for oneto a few hours.

Although the microcapsules retain a core of gas, they can be used forthe delivery of therapeutically active substances, in which case theactive substance may be included in the membrane or may be loaded in thecore. Virtually any biologically active substance can be used with themicrocapsules.

To administer the microcapsules in the context of the instant invention,the artisan “loads” the capsules according to the teaching of the '057patent and uses the resultant particles in the same manner as any otherdry powder, giving due attention to the “charge” of active agent withinthe microcapsules, the “charge” of the nebulizer and its performanceproperties, and the settings of the ventilator.

Dose-control device. The calibration test described above permits theartisan to predetermine with precision the amount of antibiotic thatshould be used to “charge” the aerosolization devices utilized in theinvention. Such charge, furthermore, is a far lesser amount than theprior art teaches (i.e., the amount that would be administeredsystemically). While syringe-like delivery can be used in the context ofthe present invention with hand-actuated pressure, such approaches runthe risk of operator error and mis-dosing. Accordingly, in a preferredembodiment, the invention provides a device comprising a pre-measureddrug reservoir sized to contain only that amount of drug desired,wherein delivery—once triggered—is automatic and complete. By makingdelivery automatic, the present invention contemplates that, whenadministered by the methods of the invention, the administered dose willelevate sputum levels of the antibiotic above MIC without elevatingsystemic levels significantly. Ideally, antibiotic levels are elevatedin the extracellular fluid on the mucosal surface of the area of thelung and/or trachea that is infected.

FIG. 8 shows one embodiment of a stand alone device which providesdose-control. In the embodiment shown, the device (100) comprises a dosemetering element (101), a fluid driving element (102), and anaerosolizing catheter (103). While it is not intended that theparticular embodiment shown be limiting in any manner, for conveniencethe device can be fashioned in two portions. The particular embodimentshown depicts a first portion of the device (comprising the dosemetering element and fluid driving element) as modular (to permit—ifdesired—single use, disconnection, and disposal of the first portion,followed by a second administration of the formulation with anothermodular unit) and configured to engage the second portion of the device(e.g. in a screw and thread engagement, 104) comprising the aerosolizingcatheter, the catheter comprising an external baffle (105)

In a preferred embodiment, the dose metering element comprises areservoir of defined volume, said reservoir (106) being preferablyconfigured as a transparent or semi-transparent cylinder or tube, withor without visible measurement indicia (107). In this preferredembodiment, the fluid formulation (e.g. antibiotic formulation) for thepatient is placed in the reservoir, the reservoir (106) being downstream(in terms of the direction of flow) of the fluid driving element (102).In a preferred embodiment, the fluid driving element comprises a plungeror piston (108) driven by compressed gas (not shown), said compressedgas stored in a container or canister (109) and released by the operatorof the device (not shown) via a trigger (110) which engages the devicethrough a port (111), allowing the trigger (110) to break arestraint/release (112) When the release of compressed gas is triggered,the plunger or piston (108) pushes the defined volume of the formulationinto the aerosolizing catheter. In a particularly preferred embodiment,the device is a “stand alone” device configured such that it can engagean opening or port in a ventilation system (e.g. see FIG. 1B), whereinsaid aerosolizing catheter (103) (having an aerosolizing nozzle, 113, atthe delivery end) is of such dimensions such that it can to fit inside(e.g. see FIG. 6)—or along side—an endotracheal tube (and/ortracheostomy tube) of an intubated patient, such that the delivery end(i.e. out of which the aerosol is delivered) of the catheter extendsapproximately to the end of the tube (or preferably below the end of thetube, thereby delivering aerosol in a manner that bypasses the tube). Ina particularly preferred embodiment, the end of the aerosolizingcatheter comprises a baffle (105) to slow the speed of the aerosol.

It is not intended that the present invention be limited by the precisedesign of the driving element, triggering elements, catheter and baffleshown in FIG. 8. Variations on these elements are contemplated, such asthose shown and described in U.S. Pat. Nos. 5,642,730, 5,964,223 and6,079,413 (all of which are hereby incorporated by reference and showvarious different designs for catheters, aerosolizing nozzles, baffles,etc) and U.S. Pat. No. 6,210,359 (hereby incorporated by reference).

In a preferred embodiment, the driving element can be avoided entirelyby the use of an Aerogen™ aerosol generator. In such an embodiment, thereservoir is placed at the delivery end of the catheter, whichterminates with the Aerogen™ aerosol generator. On the other hand, thepresent invention also contemplates substituting the aerosol nozzle inFIG. 8 with the Aerogen™ aerosol generator. Of course, the presentinvention is not confined to the current size of the commerciallyavailable Aerogen™ models. The aerosol generators may be downsized byconventional engineering in order to conveniently attach to otherdevices. For example, in one embodiment, the aerosol generator is assmall as approximately 0.4 to 10 mm, with a preferred size ofapproximately 4.0 mm (which is a convenient size for an adultendotracheal tube).

Alternatively, an aerosol generator (e.g. one of the Aerogen™ models ora scaled down version thereof) can be included in a constructed Y pieceon a vent. FIG. 12 is a schematic of one embodiment of a Y piece for usewith a ventilator, showing numerous alternative placements of an aerosolgenerator in the lower part (e.g. distal arm) of the Y piece. Indeed,the entire distal arm of the Y piece is contemplated as “aerosolcapable.” Importantly, it has been found that a more consistent dosingcan be achieved where the aerosol generator is placed below the a region(the approximate bounds of this region are shown by dotted lines in FIG.12).

In one embodiment, the aerosol generator is placed in the lower arm ofthe Y piece with a dosing catheter attached. In another embodiment, theaerosol generator is integral to the Y piece (e.g. attached, embeddedtherein, inserted, etc.) such that the delivery end (or tip) of theaerosol generator is able to deliver drug into the lumen of the tube. Inone embodiment, the aerosol generator extends into the lumen of thetube. In one embodiment, the aerosol generator extends through the wallsof the tube.

In one embodiment, the present invention contemplates that the Y piecewith the integral aerosol generator (e.g. loaded with drug at the site)is modular and can be supplied as a “stand alone” device. In such anembodiment, to deliver drug (e.g. a cocktail of antibiotics) one removesthe regular Y piece associated with commercial ventilators replacing itwith the modular Y piece comprising the aerosol generator (e.g. in themanner of an “armed warhead”). Thereafter, drug delivery is achieved byactuating the generator.

It is not intended that the present invention be limited to a preciseconfiguration of the modular tube (e.g. the upper portion of the Y tubemight be shaped as a “V”; the Y tube might be shaped more as a “T”;etc.). Similarly, it is not intended that the present invention belimited to a precise placement position of the aerosol generator in thelower arm—or the number of aerosol generators placed therein (e.g. aplurality is contemplated in some embodiments; in one embodiment, thenumber of drug-loaded generators is determined by the desired dose ofdrug—i.e. the more drug desired, the more locally drug-loaded generatorsare used). Nor is it intended that the present invention be limited toplacement of an entire aerosol generator inside the tube.

In one embodiment, the delivery end of the generator is integral to thelower arm of the Y piece, while other elements are attachable thereto.For example, in one embodiment, the drug delivery end of the generatoris attached via a conduit (e.g. a pipe, tube, channel, etc.) to a drugsupply (e.g. fluid reservoir) that is remote from the drug delivery end(e.g. aerosol head). Similarly, the force to deliver the drug may or maynot be remote from the aerosol head. Local forces might be generatedwith a battery. Remote forces might be facilitated by a variety ofappropriate energy transfer means (e.g. wire/electricity; conduit/fluidpressure and/or flow; mechanical transducers/sound).

Combination suction- and aerosol-catheter. In one embodiment of themethod of practicing the invention, an aerosol-delivery catheter isutilized and is introduced through a port in the ventilator circuit(FIGS. 2A and 2B). It is convenient to utilize a suction catheter toserve as a guide for placing the aerosol catheter by providing a channelin the suction catheter such that the aerosol catheter can be threadedtherethrough (see FIG. 6). In particular, the present inventioncontemplates an embodiment wherein a suction catheter is adapted (oradaptable) as a conduit for inserting an aerosolization catheterendotracheally. In a preferred embodiment, the suction catheter is partof the ventilator circuit, the ventilator circuit being equipped with anin-line (and in some embodiments, integral) sputum volume gauge.

In accordance with an embodiment of the present invention, a suctioncatheter, the tip of which in operation is situated distal to theendotracheally tube, is used for quantifying sputum volume in aventilated patient and to serve as a conduit for placement of theaerosolization catheter. In a preferred embodiment, the suction catheterincludes a suction tube indwelling in a pulmonary tree of a ventilatedsubject for suctioning sputum from the ventilated patient, a specimentrap for receiving and containing the sputum suctioned from the patientvia the suctioning tube, and a closeable aerosolization catheterinsertion port. The operative combination of trap and suction catheterprovide a preassembled sterile unit that is not subject to contaminationthat separate units have. Preferably, the suction catheter is attachedto the top of the trap with a sterile connection.

In accordance with other aspects of the invention, the suction cathetermay include an EBC sensor (FIG. 2C) for measuring aerosolized componentswithin the airway of the patient. A commercially available sensor whichmeasures the inflammatory mediators may be used.

Referring to the drawings, the suction catheter 10 includes a port 14which can be used either for attaching an aerosol catheter or an EBCcollection circuit. FIG. 2B shows the suction catheter 10 with aproximal end of an aerosol catheter 30 inserted in the port 14. Thedistal end of the aerosol catheter 30 is attached to a liquid feed and ahigh pressure source. In a preferred embodiment, the aerosol cathetercomprises multiple lumens. FIG. 2C shows the suction catheter 10 with aproximal end of an-EBC collection circuit 32 inserted into the port 14.The distal end of the EBC collection circuit is connected to a vaporcondenser.

By providing the port into the ventilator circuit (and in particular, aport positioned, in certain embodiments, at the end of the suctioncatheter nearest the patient), the present invention standardizes theplacement of preferred delivery means such as the catheter variouslydescribed in U.S. Pat. Nos. 5,642,730, 6,079,413 and 6,293,279 (all ofwhich are hereby incorporated by reference) so as to ensure delivery ofthe therapeutic agent directly into the relevant space (e.g. near theend of the endotracheal tube and, in preferred embodiments, just pastthe end of a properly positioned endotracheal tube) in a controlled andevenly dispersed fashion. Therefore, drugs for which dose is critical,such as antibiotics, can for the first time be administered to the lungsafely and economically. Accordingly, such dose-critical drugs are nowmore likely to be approved by regulatory agencies for administrationdirectly to the lungs. Moreover, for antibiotics specifically, theinstant invention provides a reliable and objectively measurabledelivery approach. When coupled with the above-discussed clinicalindicator(s) for commencing treatment, the combined features offeroptimum treatment results.

Preferred Drugs. Antibiotics useful in the invention asanti-gram-positive agents include the macrolides (e.g., erythromycin,clarithromycin, azithromycin) and the glycopeptides (e.g. vancomycin andteicoplanin). However, any anti-gram-positive agent capable of beingdissolved or suspended in a suitable aerosol is within the scope of theinvention (oxazoldinone, quinupristin/dalfopristen, etc.). Antibioticsuseful as anti-gram-negative agents include aminoglycosides (e.g.,gentamicin, tobramycin, amikacin, streptomycin, netilmicin); quinolones(e.g., ciprofloxacin, ofloxacin, levofloxacin); tetracyclines (e.g.,oxytetracycline, doxycycline, minocycline) and cotrimoxazole. However,any anti-gram-negative agent capable of being dissolved or suspended ina suitable aerosol is within the scope of the invention (e.g. colistin,imepinim, meripenim, etc.). Preferably, the anti-gram-positiveantibiotic and anti-gram-negative antibiotic are selected to havetherapeutic time-courses not so disparate as to result, de facto, intreating the infection serially.

The fluid that serves as aerosolization vehicle is typically a bufferedsaline solution with a pKa selected to optimize the solubility andstability of both of the antibiotics selected for a particularformulation. Other fluids, however, including lipophilic vehiclesincluding liposomes, are within the scope of the invention. For example,lipid or liposome formulated antibiotics resulting in sustained orcontrolled release of medication (e.g. Transave, SLT™ technology Inc.,ALZA's Steath Liposomal Technology, Gilead Lipsomes Drug Deliverysystems). The concentration of each antibiotic selected for use in theinvention is determined for a given aerosolization fluid by firstselecting a rate of aerosol delivery. Then a sufficient amount of eachantibiotic is added to deliver an amount to the airway of the animalthat will increase the level of antibiotic in the systemic circulationby not more than the level conventionally achieved (as measured byassays well-known in the art) when such antibiotic is administeredsystemically for the treatment of pulmonary infections. Preferably, theamount is sufficient to increase systemic levels by not more than aboutthe level generally regarded as sufficient to exert an antimicrobialeffect systemically. More preferably, the amount is less than an amountsufficient to increase systematic levels enough to exert any toxicitysystemically or to affect flora in the body elsewhere than in the areasof the lung that are infected or are at risk of becoming infected.

In one embodiment, the present invention contemplates administeringsurfactant (or, more generally, “wetting agents”) via aerosol—not forthe intrinsic therapeutic effect of the surfactant, but as a deliveryvehicle for drugs such as antibiotics. While not intending to limit theinvention to any particular mechanism, it is believed that theproperties of the surfactant operate to facilitate distribution of theantibiotic over the entire surface of the lung.

Reduced Resistance. While the successful use of the compositions,devices and methods of the present invention is not limited to anyparticular mechanisms (or the understanding of particular mechanisms),it is believed that the incidence of antibiotic resistance will declineif the high selection pressure of systemic antibiotic therapy is notpresent. Nonetheless, the compositions, devices and methods of thepresent invention can be used successfully even against a background ofsystemic antibiotic therapy. Aerosolized antibiotics prevent thedevelopment of resistance in the presence of systemic antibiotics.

In one study, of 9 patients receiving aerosolized antibiotics, 3developed newly resistance organism while on systemic therapy. On theother hand, among the 8 control patients on placebo, 5 patients out ofeight on systemic therapy developed a newly resistance organism. Thisdata suggests that i) aerosol administration reduces the incidence ofresistance; and ii) decreased resistance is not simply a benefit of theaerosol approach, it is an intrinsic property of the aerosol approach.

Drug-Impregnated Tubes. One aspect of the present invention contemplatesan endotracheal tube or tracheostomy tube impregnated with one or moreantimicrobials. In a preferred embodiment, a mixture of at least onegram-positive and one gram-negative antibiotic is used. In oneembodiment, the antibiotic mixture may be applied as a surface coatingof the endotracheal tube. In another embodiment, the antibiotic mixturemay be incorporated into the endotracheal tube matrix duringmanufacturing. In one embodiment, the antibiotic mixture is applied tothe entire endotracheal tube. In another embodiment, the antibioticmixture is applied to the cuff and/or tip of the endotracheal tube.

Polymer surface coatings are known to provide long-duration release ofantibiotics and other drugs from polymer surface coatings. Thistechnology requires post-manufacture application of a polymer/antibioticmixture to the surface of the endotracheal tube. Shikani et al., U.S.Pat. No.: 5,762,638; and Domb et al., U.S. Pat. No.: 5,512,055 (bothherein incorporated by reference). Polymer coatings contemplated by thepresent invention may be applied to the exterior surface of theendotracheal tube. In certain embodiments, the polymers comprising thesecoatings may exhibit, but are not limited to, the followingcharacteristics: i) the polymers are soluble or dispersible in solutionin order to be disposed onto the outer surface of the endotracheal tube;ii) the polymers do not chemically react with any of the contemplatedantibiotics; iii) the polymers are compatible with all of thecontemplated antibiotics and form a uniform, solid, complex; iv) thepolymers are capable of forming a uniform coating on the surface of thetracheal tube; v) the polymers are capable of forming polymer-antibioticcomplexes which remain stable during storage, use and disposal thereofwithout significant loss of antibiotic. It is preferred that thecontemplated polymers are both biocompatible and nonbioerodible. Boththese characteristics ensure that the polymers will not react with bodytissues nor be inadvertently released into the patient's body,respectively. The polymers contemplated by the present inventioninclude, but are not limited to, polyurethane, polyurea, ethylene vinylacetate, polyvinylchloride, polyesters, nylon, polycarbonate,polyethylene, polymethyl methacrylate, cellulose esters (i.e., ethyl,methyl and propyl), polypropylene, polystyrene, polyterefluoroethylene,poly(ethylenevinyl acetate), elastomeric organosilicon polymers,poly(hydroxy alkyl esters, copolymers and combinations thereof.Preferably, the coatings are between 0.01 and 1.0 mm thickness and, mostpreferably, between 0.1 and 0.22 mm thickness. The polymer coatings maybe formed by solvent casting, melting, dipping, spraying, brush coatingor any other suitable method.

Endotracheal tubes impregnated with mixtures of gram negative and grampositive antibiotics may be constructed during manufacture. Theliquified polymer is loaded with a mixture of gram negative and grampositive antibiotics. To disperse the antibacterial mixture into thepolymer, techniques such as mixing the antibiotics directly into thepolymer or solvent evaporation techniques such as those disclosed inU.S. Pat. Nos. 4,310,509 and 4,643,181 are used, both herebyincorporated by reference. Solvent evaporated techniques typicallyinvolve forming an emulsion of the antibiotics in a solvent, and mixingthe emulsion into the polymer so that the antibiotics are uniformlydispersed as a separate phase throughout the polymer mixture. Thesolvents used to form the emulsion may be a single type of solvent or acombination of solvents selected from water or water soluble solventssuch as methanol, ethanol, ethyl acetate, tetrahydrofuran and the like.Mixing of the emulsion typically occurs at low mixing rates, about 300rpm, and at ambient temperatures. The antimicrobial agent is preferablypresent in an amount of about 0.1% to about 25% by weight of adhesive,more preferably about 1% to about 5% by weight. When using hydrophilicadhesives, amounts less than 1% may be used. This mixture is extrudeduntil properly mixed and molded into an endotracheal tube including thecuff and tip areas. The polymer is allowed to solidify and is thenremoved from the mold. The catheter is then wiped with an isopropylalcohol (w/w 30/40/30) solution. Alternatively, the antibioticcontaining liquified polymer is limited to the mold area consisting ofthe cuff and/or tip areas of the endotracheal tube, whereas theremainder of the endotracheal tube is molded without a mixture ofantibiotics in the liquified polymer.

Importantly, the measurement of sputum levels in the patient iscontemplated as a convenient way to measure the efficacy of embodimentsof impregnated tubes. For example, it is contemplated that newendotracheal tubes with impregnated antimicrobials (e.g. coatings on theentire device, coatings on the tip and/or cuff area of the device, etc.)can be compared with one another, other tubes, or the same tube (albeitwithout impregnated drug) on the basis of sputum levels (or othermeasurements associated with infection described above). Sputum levelsoffer a convenient readout in that they can be readily measured as afunction of time over the intubated period. It is expected that certainimpregnated embodiments will prevent or at least delay the onset ofincreased secretions, and consequently the onset of tracheobronchitisand VAP. The present invention contemplates that the testing of suchdevices (including but not limited to the testing in clinical trials)can be enhanced by using the sputum level test (described above) with orwithout other indicators of disease.

The examples below are merely provided to illustrate certain embodimentsin greater detail and are not intended to be limiting in any manner.

EXAMPLE 1

An aspect of the present invention may be regarded as a method forquantifying sputum volume in a ventilated patient. In one embodiment,the ventilated patient is suctioned until there are no furthersecretions. The ventilated patient is then suctioned for a predeterminedtime period. If there is a predetermined amount of sputum while theventilated patient has been suctioned up to the predetermined timeperiod, the sputum is cultured and analyzed. A therapy order is writtenbased on the analyzed culture.

In accordance with other aspects of the invention, the ventilatedpatient is suctioned early in the morning (e.g, at 6:00 A.M.) untilthere are no further secretions. The ventilated patient is suctioned asecond time later in the morning (e.g., at 8:00 A.M.) until there are nomore secretions.

In accordance with still other aspects of the invention, the ventilatedpatient is suctioned hourly for four hours. In accordance with yet otheraspects of the invention, the predetermined amount of sputum is about 2cc.

In accordance with further aspects of the invention, the therapy orderis an order for aerosolized antibiotics to be delivered directly to thelungs.

In accordance with a related aspect of the invention, delivery of theaerosolized antibiotics is effected via an aerosolization catheterintroduced directly into the lungs via the suction catheter.

In a still further related aspect of the invention, aerosol delivery viathe aerosolization catheter is actuated by means of a pump and pressure,which pump and pressure feed may be integral to a mechanical ventilatoror, optionally, independent thereof.

In accordance with yet further aspects of the invention, an initialtherapy order is written prior to analyzing the culture and the initialtherapy order is modified after the culture is analyzed.

In accordance with still further aspects of the invention, inflammatorymediators in the sputum are measured. The inflammatory mediators mayinclude TNF-alpha, interleukin-1-beta, and soluble-ICAM. These levelsare measured on sol levels of the sputum using commercially availableELISA kits. Rising levels of these cytokines imply worseninginflammation.

In accordance with yet other aspects of the invention, aerosolizedcomponents of exhaled breath condensate (EBC) are measured. Theaerosolized components may include TNF-alpha, IL-1 beta, IL-8, H₂O₂,nitrates, and nitrites.

EXAMPLE 2

Embodiments of the present invention provide a system and method fordefining risk for and prevention of ventilator associated pneumonia. Themethod comprises means for quantifying sputum volume in mechanicallyventilated patients and interpreting the value obtained by using areference database in which pneumonia risk data and sputum volumes arecorrelated. Alternatively, or in combination with sputum volumemeasurements, the method comprises means for measuring the flux ofinflammatory cells or mediators of the inflammatory process in thesputum over time. The system in one embodiment comprises a suctioncatheter adapted for practice of the method and for administering thetreatment via an aerosolization catheter. In exemplary embodiments, thesystem also enables measurements of volatile or aerosolized componentsof exhaled breath condensate (EBC) that are reflective of developingbacterial infection. Exemplary embodiments of the present inventionprovide a means for determining the total inflammatory burden of theairway.

Referring now to the drawings wherein the showings are for purposes ofillustrating preferred embodiments of the present invention only, andnot for purposes of limiting the same, FIG. 2A illustrates a suctioncatheter 10 with an integral sputum volume gauge 12 and anaerosolization insertion port 14 with closure means 16 formed inaccordance with the present invention in use on a ventilated patient 20.As is well known, sputum comprises the material that is coughed up fromthe windpipe, bronchi, and lungs. A small amount of clear sputum isnormally produced by the lungs each day. The amount of clear sputumincreases in any minor respiratory infection. The sputum volume gauge 12of the present invention allows for the measuring and analyzing thesecretions in ventilated patients 20 in order to determine whattreatment, if any, should be prescribed for the ventilated patient.

The volume of secretions in ventilator patients has been studied inpilot studies. These studies generated the fundamental data leading tothe development of the device of the present invention and the conceptof using volume assessment as a clinical endpoint. This early data wasfollowed by an investigation that determined the amount of secretions ofall newly intubated patients over the first two weeks of theirrespiratory failure. This investigation demonstrated that:

-   -   (1) secretions increased the second week of intubation; and    -   (2) patients with pneumonia had a measurably significant        increase in secretions compared to those patients who did not        have pneumonia.

EXAMPLE 3

Experiments have shown a marked increase in secretions in those patientswho had pneumonia compared to those patients without pneumonia. Theamount of secretions increased during the second week in those patientswithout pneumonia. More specifically, the sputum volume for patientswith pneumonia increased from approximately 6 ccs in the first week ofventilation to approximately 8 ccs in the second week. For patients nothaving pneumonia, the sputum volume increase from approximately 1 cc inthe first week to approximately 2 ccs in the second week.

Data supporting the validity of sputum volume as a marker ofinflammation was demonstrated in investigations examining therelationship between sputum volume and inflammatory cells and cytokines.Aerosolized antibiotics were administered to chronically ill stablepatients requiring mechanical ventilation. Treatment caused asignificant reduction in the volume of secretions (p=0.002). In additionthere was a marked reduction in organisms in these patients. Further,volume of secretions was related to neutrophil concentration, r=0.502,p=0.008. Further IL-1β was also related to volume, r=0.589, p<0.006.

Neutrophils increase significantly with volume. These cells may becausative as inflammatory mediators released from them may augmentmucous production.

EXAMPLE 4

To further assess the effect of treatment on airway inflammation, amethod of assessing the total “inflammatory burden” to the airway wasdevised by calculating the flux of inflammatory cell or mediators overtime. Volume measurement is performed for a specified period. Cell countand differential cell count of types of inflammatory cells are performedon the tracheal aspirate. Inflammatory cytokines are measured from thesol phase of the sputum. The airway burden is defined for eachinflammatory parameter using the following equations:Neutrophil airway burden=(TCC) cell/gm tracheal aspirate(%neutrophils)(ml/6 hours)andsICAM-1 burden=sICAM-1 ng/ml (ml/6 hours)

There are two components to the total amount of inflammatory mediatorsin the airway over time. One is their concentration and the second isthe volume of secretions over time. The total amount of mediator overtime is reflected in this measurement. Neutrophil cell burden decreasedsignificantly by 7 fold (p<0.014) and sICAM-1 increased by 2.5 fold(p<0.034). This method gives a direct quantitative measurement of thetotal airway inflammation at any point in time, whether a patient is offtreatment or is on treatment, thus allowing real time measurement ofneed for response to treatment rather than waiting for a more ultimateand dire outcome such as survival.

Establishing clinical endpoints remains a major challenge in studiesdesigned to prevent or treat ventilator associated infections. The 4hour collection is a potentially important means for evaluating airwaypathophysiology and response to drug therapy. Increases in sputum volumenoted by nursing staff by gross visual assessment often trigger work upor treatment for tracheobronchitis by critical care specialists. Inorder to eliminate the inaccuracies of subjective impressions of sputumvolume which are dependent on frequency and method of suctioning wedevised the quantitative volumetric assessment over a 4 hour time periodWe have previously documented a decrease in volume in patients afteraerosolized antibiotic therapy.

In this study, the decrease in respiratory secretions was associatedwith a marked reduction in Gram-negative isolates with eradication ofall organisms in six out of nine trials. Further more, Gram-stains inseven out of nine trials had no Gram-negative bacilli during treatmentsuggesting the bacterial population had not been reduced only incultures test but had been markedly decreased in the airway. There wereno significant side effects. Despite very high sputum levels, serumlevels were low or non detectable except in the one patient with renalfailure. In addition, the emergence of persistently resistant isolatesseen in prior human and animal studies involving topical therapy to thelower respiratory tract was not observed. Only three of twenty isolateswere resistant post treatment and none were detected two weeks posttreatment. The reason for the lack of resistance is unknown. Thepatients were not all treated at the same time, nor for as long a timeas in previous studies. Further, the total dose of the drug to the bodyis less than in selective decontamination and the effects on total bodyflora are probably reduced. Additionally, the drug is delivered“directly” to the target organ, leaving the mouth and gut unaffected.

In vitro studies have shown that gene expression of theseproinflammatory cytokines, TNF-alpha and Il-1β, is markedly augmented bylipopolysaccharides from Gram-negative bacilli and they in turn inducesynthesis of endothelial adhesion molecules and other chemotacticcytokines. These molecules appear to regulate the influx of inflammatorycells, their activation, and release of enzymes such as elastase. Invivo human data are limited primarily to cytokine levels from patientswith septic shock, trauma and ARDS when BAL and sputum levels ofTNF-alpha and I1-1β have been reported to be elevated. In these unstablesyndromes it is difficult to distinguish a systemic inflammatoryresponse from a pulmonary process mediated by cytokines derived fromalveolar macrophages and other airway cells.

This was the first study to assess the effect of a specific therapy onthe relationship of these cytokines to airway inflammatory cells andvolume of secretions. We measured effects of drug delivery on indices ofairway inflammation including TNF-alpha, Il-1β, sICAM-1 and neutrophilelastase. Not only was the volume decreased with aerosolized antibioticsbut the decrease correlated with IL-1β and with neutrophilconcentration. It was found that the concentration of Il-β correlatedwell with numbers of macrophages/gm (r=0.744, p<0.002), neutrophils/gm(r=0.710, p<0.0004) and lymphocytes/gm (r=0.597, p=0.005). This is ofinterest as macrophages are the primary cell of origin for Il1-β andthis cytokine may assist in increased recruitment of neutrophils.

Treatment was associated with an increase of sICAM-1. This may representincreased shedding of membrane bound ICAM-1 from the surface epitheliumduring antibiotic therapy when the reduction in Gram-negative isolatesmay have been associated with a down regulation of neutrophil flux.Conversely, levels of sICAM-1 correlated inversely with levels of humanleukocyte elastase (r=0.606, p=0.008) suggesting decreased shedding ofmembrane bound sICAM-1 during neutrophil recruitment when airwayinflammation and elastolytic activity were maximal.

In summary, these studies show that nebulized antibiotics can beeffectively delivered to mechanically ventilated patients and that thistreatment results in measurable changes in clinical and airwayinflammatory indices. Selective therapy with aerosolized antibiotics asdescribed in this invention, specifically targeted to patients withincreasing inflammatory secretions might decrease the incidence ofnosocomial pneumonia while preserving oral and gut flora with limitedbacterial resistance.

EXAMPLE 5

The embodiments of the device of the present invention assess sputumvolume, which is used as an endpoint to trigger treatment forrespiratory infection prior to the development of radiographicallydiscernible pneumonia. One embodiment of the device of the presentinvention 10 measures sputum volume in a suction tube 18 indwelling inthe pulmonary tree of a ventilated subject. This device 10 determineswhich mechanically ventilated patients 20 would benefit from treatmentof airway infection before it progresses to pneumonia. In addition tothe suction catheter, the present invention includes a sterile specimentrap 12, which contains a maximum of 2 cc of sputum.

In exemplary embodiments, the present invention is used with thefollowing protocol shown in FIG. 14. First, at 6:00 A.M., the patient issuctioned until no further secretions can be obtained (block 100). Thisensures that the secretions that may have accumulated over night are notincluded in the timed quantitation period. No saline is used in therespiratory tract after this time. Any addition of saline willinvalidate the volume of aspirate as this will no longer representvolume of airway secretions. Next, at 8:00 A.M., the patient issuctioned until free of secretion (block 102). The device 10 is placedin the suctioning circuit between the suctioning catheter and thenegative pressure vacuum on the wall. The device 10 is made of plasticand must be sterile for use. While the device 10 requires nocalibration, it does require a very specific protocol for suctioningwhich is part of its design.

The patient is suctioned hourly for four hours or until the sputum tap12 is filled with 2 cc of secretions (block 104). If after four hours,there is less than 2 cc (no in decision block 106), the device 10 istaken out of the circuit line and discarded (block 108). If, however,there are at least 2 ccs (yes in decision block 106), the device is sentto Microbiology for culture and sensitivity analysis (block 110). Anorder is written to start the patient on aerosolized antibiotics at thispoint (block 112). Prior cultures or the predominant organism in theintensive care unit guides the antibiotic chosen. When the cultureresults are back (block 114), the order is modified (block 116).

Other embodiments of the present invention include a double endpointdiagnostic method comprising the contemporaneous measurement ofsuctioned sputum volume and the presence/level of inflammatory mediatorsin the sputum including, but not limited to, TNF-alpha, interleukin1-beta, and soluble ICAM-1. The quantity of these mediators is doserelated to sputum volume. Therefore, sputum volume and quantity ofsampled mediators/molecules indicate developing infection.

Other embodiments of the present invention include a sputumvolume/inflammatory mediator method that includes the measurement ofvolatile or aerosolized components of exhaled breath condensate (EBC)that are reflective of developing bacterial infection. EBC has been usedto detect degrees of inflammation, but it has not been used to diagnoseinfection.

Various embodiments of the invention include a triple endpointmeasurement wherein sputum volume, sputum mediators/molecules andcondensate mediators/molecules together may be used to define thepresence of bacterial infections. The suction catheter includes an EBCsensor as an integral part of its inline function. An EBC/volumetricdevice is placed in on the first day of mechanical ventilation and everyday thereafter while this modality is required. Measurements ofTNF-alpha, Il-1 beta and I1-8 (proinflammatory cytokines) in thesecretions are monitored in addition to specific bacterial metabolicproducts in the breath condensate, e.g., H₂O₂, nitrates, nitrites andother nonspecified products. The integrated volume, secretion, and EBCinflammatory data quantifies the real-time changes on a daily basisproviding information for therapeutic measure.

Exemplary embodiments of the present invention for treating and orpreventing pneumonia by assessing the severity thereof according to asputum volume test and devising an appropriate dosage regimen therefromspecify the use of Targeted Aerosolized Antibiotics (TAA) in thosepatients with increased secretions and inflammatory mediators/molecules.Patients who have increased volume and inflammation related to bacterialinfections as determined by the volumetric/secretion/EBC device arebegun on aerosolized antibiotics via the delivery catheter. Thisrepresents the concept of TAA.

Therapy is given for a defined period in only the targeted group. Thislowers the antibiotic exposure to the patient and to the critical careunit environment. This is a fundamental aspect of this treatment asearlier studies using continuous topical therapy to all ventilatorpatients led to highly resistant organisms.

TAA leads to a fourfold improvement in patient outcome: (1) reducedincidence of ventilator associated pneumonia; (2) deceased days onmechanical ventilation; (3) decreased use of systemic antibiotics; and(4) decreased antibiotic resistance.

In order to confirm the reduction in the reduced incidence of pneumonia,an accurate and consistent means of diagnosing pneumonia is needed. Thepresence of fever, new infiltrate, leukocytosis, or leukopenia, purulentsecretions and a quantitative bronchoalveolar lavage demonstratinggreater than 10,000 colony forming units can be used. Using thismethodology, endpoints can be compared which include:

-   -   (1) the incidence of pneumonia in those patients with increased        volume and inflammation;    -   (2) the incidence of pneumonia in patients who receive        aerosolized antibiotics versus placebo;    -   (3) the resistance patterns for treated patients versus the        patterns in the intensive care unit environment;    -   (4) antibiotic use: number of antibiotics days/per        patient=number of antibiotics per day times number of days in        each critical care unit (e.g. 2 antibiotics per day times 7        days=14 antibiotic days); and    -   (5) length on mechanical ventilation in treated and untreated        patients.

EXAMPLE 6

FIG. 15A shows a ventilator circuit (1000) comprising i) an inspiratoryline (1001) and an expiratory line (1002) coming from a ventilator(shown as a box labeled “VENT”) and converging at a junction (1003)(typically a “T” or “Y” junction), ii) a nebulizer (1004) positioned inproximity to said junction (e.g. attached to the stem (1005) or integralto the stem) and in fluid communication with a tracheostomy tube (1006)(or alternatively an endotracheal tube), wherein said nebulizer (1004)is not positioned in said inspiratory line or said expiratory line.While it is not intended that the present invention be limited to howthe nebulizer is attached, FIG. 15A shows an embodiment wherein aY-piece junction is attached to a commercially available T-piece (1007),wherein the Y-piece stem (1005) is connected to one arm of the T-piece(1007), and wherein the T-piece stem (1008) is connected to thenebulizer (1004).

FIG. 15B shows a ventilator circuit comprising i) an inspiratory lineand an expiratory line converging at a junction (typically a “T” or “Y”junction), ii) a nebulizer positioned in proximity to said junction(e.g. attached to the stem or integral to the stem) and in fluidcommunication with an endotracheal tube, and a removeable inhaled massfilter positioned between the nebulizer and the endotracheal tube,wherein said nebulizer is not positioned in said inspiratory line orsaid expiratory line. The inhaled mass filter allows one to do accuratemeasurements of what delivery amounts are actually reaching the patient.

In a first experiment, the arrangements of FIGS. 15A and 15B were usedwith two different commercially available ventilators: the T-Birdventilator, the Drager ventilator. The nebulizer actuation was examinedin “continuous” mode as well as in a “breath actuated” mode. Thehumidity feature for these ventilators was examined by performing thetest both when the feature is active and when it is off. An expiratoryline filter was also used (not shown). Table 1 summarizes the data (as apercentage of nebulizer charge). Clearly, there is an advantage whendelivering the aerosol (of albuterol) when the humidity feature is offand not active. When administration is breath actuated, the amount ofdrug on the expiratory filter drops by approximately 50% and there issome increase in inhaled mass when administration is breath actuated.Most importantly, the data reveal a narrow range (a range ofapproximately three percentage points) of inhaled mass (i.e. goodcontrol over the dose).

When compared with conventional arrangements for aerosolization, thedata reveals that the placement of the nebulizer such that it is not inthe inspiratory line improves control over the delivery dose. A morereproducible dose is delivered using the arrangement where the nebulizeris not in the inspiratory line (such as that shown in FIGS. 15A and B).

Importantly, while FIGS. 15A and 15B show the placement of the nebulizerat a particular position, the present invention contemplates embodimentswherein the nebulizer is not directly attached to the Y piece, but isplaced closer to the patient (indeed, placed anywhere between the Ypiece and the patient). Such alternative placements still avoid thenegative effects of the ventilator circuit.

In a second experiment, the arrangements of FIGS. 15A and 15B were usedwith a single commercially available ventilator (the T-Bird ventilator)together with three different commercially available nebulizers. Thenebulizer actuation was examined in the “continuous” mode. The humidityfeature for these ventilators was examined by performing the test bothwhen the feature is active and when it is off. An expiratory line filterwas also used (not shown). Table 2 summarizes the data (as a percentageof nebulizer charge). Clearly, the Portex nebulizer performed poorlyunder these conditions. The Aerotech and Aerogen nebulizers appeared tobe relatively insensitive when delivering the aerosol (either gentamicinor vacomycin) to the humidity feature, although there is some benefit tohaving the humidity feature turned off and not active. Interestingly,the inhaled mass is similar for both antibiotics.

EXAMPLE 7

FIG. 16 shows one embodiment of a bench model which can be used witheither a nebulizer (shown as a box attached at the Y piece of FIG. 16A)or an aerosol catheter (the arrow in FIG. 16B indicates the catheter canbe positioned in the ET tube). FIG. 16 shows a ventilator circuitcomprising i) an inspiratory line and an expiratory line coming from aventilator (not shown) converging at a junction (typically a “T” or “Y”junction). The endotracheal tube (or tracheostomy tube), instead ofbeing in the patient, is attached to 100 ml tube, which models theproximal airways (trachea and mainstem bronchi); the 100 ml tube isattached to the inhaled mass filter. In other words (describing thearrangement moving in the direction of the patient), the Y piece isconnected to the ET tube, which is connected to the 100 ml tube, whichis attached to the inhaled mass filter (the filter measures aerosol thatwill pass out of the proximal airways and enter the distal lung).

In a first experiment, the bench model of FIG. 16B was tested with anaerosol catheter (the Trudell catheter, Trudell Medical International);a standard Y-piece was used (without any nebulizer). Radiolabeledalbuterol aerosol was generated and introduced via the catheter into theET tube. The inhaled mass was measured in two parts: the proximalariways (100 ml tube) and distal airways (filter distal to the 100 mltube). The Mass Median Aerodynamic Diameter (MMAD) was measured inaerosol delivered to distal airways using a cascade impactor. The testwas performed with two different ventilators with the humidity featureactive and off. Administration of the aerosol was continuous (not breathactuated). The results are shown in Table 3. The data reveal thatadministration of aerosol in this manner is relatively insensitive tohumidity. Interestingly, the majority of drug is deposited in the 100 mltube (modeling the proximal airlways) with smaller amounts in the filter(distal lung). These data suggest that the ET tube and trachea will bemajor sites of deposition when the delivery end of the catheter iswithin the ET tube. The results suggest delivery to the distal airwaysis comparable to that achieved with the nebulizer.

In a second experiment, a Trudell catheter was used to administeraerosol into the ET tube in a breath actuated mode using the bench modelof FIG. 16B (again no nebulizer was used) and a single ventilator.Inhaled mass was measured using only the filter (a second filter in theexpiratory line was also used). Both albuterol and gentamicin weretested. The results are shown in Table 4 and reveal that the Trudellcatheter behaves in a manner that is largely independent of theconditions set by the ventilator (e.g. humidity). Breath actuationclearly increased the inhaled mass and the narrow range of depositionshows that this mode of administration provides good control over thedose.

Attempts to administer vancomycin in the same manner as gentamicinencountered difficulties; vancomycin can cause blockages of the catheterwhen operated in the breath actuated or pulsed mode. On the other hand,vancomycin aerosols have been successfully created in the continuousmode of operation using existing formulations.

EXAMPLE 8

FIG. 17 shows various embodiments of a device for attaching a nebulizerto a ventilator circuit. The device can be generally characterized as asingle piece of tubing or conduit, said device comprising two or threeopen ends (optionally, said ends have different inner diameters) andpermitting fluidic communication between the elements attached to saidends. FIG. 17A shows a one piece adapter (1701) configured on a firstend (1702) for attachment to a Y-piece (1703), configured on a secondend (1704) for attachment to an endotracheal tube (1705) (ortracheostomy tube), and configured on a third end (or “stem”) (1706) forattachment to a nebulizer (not shown). It is not intended that thepresent invention be limited to the particular attachment means. In oneembodiment, attachment is achieved using tubing of different diameters.For example, FIG. 17A shows the tubing of the endotracheal tube (1705)has a smaller diameter than the second end (1704) of the adapter (1701)so that it can slide in and en gage the adapter (1701). Alternatively,the adapter end could have a smaller diameter and could slide inside theET tube. While not limited to precise dimensions, in one embodiment, theouter diameter of the endotracheal tube (1705) is approximately 15 mmand the inner dimension of the second end (1704) of the adapter (1701)is approximately 15 mm to create a tight male/female friction fit.Again, while not limited to precise dimensions, in one embodiment, theouter diameter of the Y-piece stem is 22 mm and the inner diameter ofthe first end (1702) of the adapter (1101) is 22 mm. Alternatively, theattachments can be snap fit or screw fit (e.g. one or more ends of theadapter are threaded).

FIG. 17B shows a one piece adapter (1707) configured on a first end(1708) for attachment to a Y-piece (1709), configured on a second end(1710) for attachment to an endotracheal tube (or tracheostomy tube)(1711), and configured on a third end (1712) (or “stem”) for attachmentto a nebulizer (not shown), wherein said second end (1710) comprises aflexible section (1713). It is not intended that the present inventionbe limited to the particular attachment means. In one embodiment,attachment is achieved using tubing of different diameters. For example,FIG. 17B shows the tubing of the endotracheal tube (1711) has a smallerdiameter than the second end (1710) of the adapter (1707) so that it canslide in and engage the adapter (1707) in a male/female friction fit.Alternatively, the adapter end diameter could be smaller and could slideinside the ET tube. Alternatively, the attachments can be snap fit orscrew fit (e.g. one or more ends of the adapter are threaded).

FIG. 17C shows a one piece adapter (1714) with an integral nebulizer(1715), said adapter (1714) configured on a first end (1716) forattachment to a Y-piece (1717), and configured on a second end (1718)for attachment to an endotracheal tube (or tracheostomy tube) (1719),wherein said second end (1718) comprises a flexible section (1720). Itis not intended that the present invention be limited to the particularattachment means. In one embodiment, attachment is achieved using tubingof different diameters. For example, FIG. 17C shows the tubing of theendotracheal tube (1711) has a smaller diameter than the second end(1710) of the adapter (1707) so that it can slide in and engage theadapter (1707) in a male/female friction fit. Alternatively, the adapterend diameter could be smaller such that it could slide inside the ETtube. Alternatively, the attachments can be snap fit or screw fit (e.g.one or more ends of the adapter are threaded).

The adapter (1714) shown in FIG. 17C could be molded as a single unit(the nebulizer as an integral part). Alternatively, the adapter (1714)could be molded as two (or more) parts (e.g. the nebulizer is moldedseparately and thereafter attached). The nebulizer could be drug loadedor empty. The nebulizer can have one or more ports (1721) forapplication of gas or liquid.

1-13. (canceled) 14-21. (canceled)
 22. A device comprising tubingconfigured approximately as a Y piece, said device having a first endattachable to a ventilator and a second end attachable to anendotracheal tube, wherein said second end comprises an aerosolgenerator.
 23. The device of claim 22, wherein said aerosol generator isintegral to said second end.
 24. The device of claim 23, wherein saidaerosol generator is drug-loaded.